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Shelby Dakota cooling setup inquirery


Phatnlow

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I am purchasing (on lot finacing) my Shelby Dakota from a local used car lot they had just put a new radiator in it. The 5 times i drove the truck here locally within 20 miles it never overheated of course the outside temps were below 50 degrees the temp gauge would get almost 1/4 way up then the fan would kick in dropping the temp gauge way down to the bottom. Last Wednesday i was stuck waiting on our local school to let out the outside temp was around 65 degrees i noticed the temp gauge was alittle over halfway so i shut the truck off then we started moving so i drove straight home which was 4 miles pulled into the garage and popped the hood and it was boiling ( lost about a quart of antifreeze) The fan was kicking in but didn't notice if it was kicking in frequently enough. Mine is wired with a switch under the dash to manually turn on the fan but it is now disconnected from the battery and fan wires are still there tucked down beside the battery. 1st. question- Did these trucks have a radiator shroud on them when new? Mine doesn't have one. 2nd. question- My local autoparts store said i need to check the fan switch first. Where is the switch? 3rd. question- Can the motors on these original fans be replaced if needed? Or is there a better replacement option? Any help on this topic would greatly be appreciated.

Thanks Leonard

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Mine did not have a shroud either because there is no fan connected to the engine water pump. The electric fans should be wired with a relay and thermostat to the battery so the fan comes on when needed and off when not required. The switch in the dash must be a home made job. I have not seen any company with replacement motors but I would think there has to be someone who makes a replacement.

 

Bob

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The electric fans should be wired with a relay and thermostat to the battery so the fan comes on when needed and off when not required.

Actually when the Shelby Dakota's left the Shelby plant, the electric fans were wired to a relay controlled by the engine controller. the Shelby Dakota engine controllers were modified by Shelby to control the electric fans. They came on and went off by direction from the ECU. I don't recall what the trigger on/off temps are, but it was all based on what the engine temp sensor reported.

 

Over the years, some Shelby Dakota's have had engine controller failures and it is impossible to get replacements. Many times when folks sent their ECU in for repair they would get a stock 1989 Ram 318 controller back (some folks were sent V6 controllers as that is what the trucks came from Dodge with).

 

As a fix, folks found one of the 1989 Ram ECU's and put that in their Shelby Dakota's, and wired the electric fans as you mention above.

 

And you are correct as to the reason there wasn't a fan shroud. When Shelby fit the 318 into the Dakota, it was felt there wasn't quite enough clearance for the stock fan mounted on the water pump snout. And that is why the electric fans were used as a substitute.

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Actually when the Shelby Dakota's left the Shelby plant, the electric fans were wired to a relay controlled by the engine controller. the Shelby Dakota engine controllers were modified by Shelby to control the electric fans. They came on and went off by direction from the ECU. I don't recall what the trigger on/off temps are, but it was all based on what the engine temp sensor reported.

 

Over the years, some Shelby Dakota's have had engine controller failures and it is impossible to get replacements. Many times when folks sent their ECU in for repair they would get a stock 1989 Ram 318 controller back (some folks were sent V6 controllers as that is what the trucks came from Dodge with).

 

As a fix, folks found one of the 1989 Ram ECU's and put that in their Shelby Dakota's, and wired the electric fans as you mention above.

 

And you are correct as to the reason there wasn't a fan shroud. When Shelby fit the 318 into the Dakota, it was felt there wasn't quite enough clearance for the stock fan mounted on the water pump snout. And that is why the electric fans were used as a substitute.

 

Good info, I stand corrected. Thanks, Bob

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  • 2 weeks later...

I tested both the electric fans by running 2 jumpers straight to the battery and they both work. I keep the battery unhooked while restoring the truck inside/outside (it's of course not my everyday driver) so it won't drain the battery when i leave the doors open. I asked my local nissan mechanic and he said there might be 2 coolant temperture switches 1 for the gauge and 1 for the fan he also said a relay normally doesn't go bad-i dunno myself. Is the temp switch (2 wire screwed into the intake manifold) right in the thermostat neck area?? Do you'all know if there's 2 coolant temp switches?? I noticed today (friday the 2nd) when i drove it the gauge showed 1/4 the way up but when i got home it was gurging. I don't drive any futher than a few miles watching and i checked i have normal heat. Any help would be great!!

Thanks so far for all of your help...

 

Everyone have a safe Happy Easter!!!!!

Leonard :D

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I tested both the electric fans by running 2 jumpers straight to the battery and they both work. I keep the battery unhooked while restoring the truck inside/outside (it's of course not my everyday driver) so it won't drain the battery when i leave the doors open. I asked my local nissan mechanic and he said there might be 2 coolant temperture switches 1 for the gauge and 1 for the fan he also said a relay normally doesn't go bad-i dunno myself. Is the temp switch (2 wire screwed into the intake manifold) right in the thermostat neck area?? Do you'all know if there's 2 coolant temp switches?? I noticed today (friday the 2nd) when i drove it the gauge showed 1/4 the way up but when i got home it was gurging. I don't drive any futher than a few miles watching and i checked i have normal heat. Any help would be great!!

Thanks so far for all of your help...

 

Everyone have a safe Happy Easter!!!!!

Leonard :D

 

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The manager at Autozone just told me first check and replace the electric fan relay. He said a relay will get stuck or stop working all at once unlike a coolant temp sensor. He told me you don't want to wire the fan to a on/off switch like what was done years back because it's not good on the fan motor to run so much even when not needed all the time. Which makes perfect sense. Has anyone figured out which relay is connected to the electric fan? The rectangular silver metal capped relay closest to the firewall allows the engine to start. Of course the Bosh one is for the driving lights. I'm going to keep testing an pray.

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The manager at Autozone just told me first check and replace the electric fan relay. He said a relay will get stuck or stop working all at once unlike a coolant temp sensor. He told me you don't want to wire the fan to a on/off switch like what was done years back because it's not good on the fan motor to run so much even when not needed all the time. Which makes perfect sense. Has anyone figured out which relay is connected to the electric fan? The rectangular silver metal capped relay closest to the firewall allows the engine to start. Of course the Bosh one is for the driving lights. I'm going to keep testing an pray.

 

 

On the left fender side shield is a pack of 3 relays, when facing them, from left to right they are, fan relay, auto-shutdown relay, and the A/C clutch relay.

 

BTW, there are Shelby Service Manual Supplements that document all of the changes Shelby made to the vehicles. They include wiring diagrams, and in the case of the cooling system and electric fans, a fairly comprehensive testing / diagnosis procedure. It includes what temps and driving conditions the fan should be on and off.

 

I believe Steve (shelbymotorsports) sells the supplements, and the Shelby Dodge Auto Club also does. SDAC gets $15 for them which includes shipping. The one for the Shelby Dakota is 24 pages, is loose leaf style and 3-hole punched, not bound like Steve's are.

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I tested both the electric fans by running 2 jumpers straight to the battery and they both work. I keep the battery unhooked while restoring the truck inside/outside (it's of course not my everyday driver) so it won't drain the battery when i leave the doors open. I asked my local nissan mechanic and he said there might be 2 coolant temperture switches 1 for the gauge and 1 for the fan he also said a relay normally doesn't go bad-i dunno myself. Is the temp switch (2 wire screwed into the intake manifold) right in the thermostat neck area?? Do you'all know if there's 2 coolant temp switches?? I noticed today (friday the 2nd) when i drove it the gauge showed 1/4 the way up but when i got home it was gurging. I don't drive any futher than a few miles watching and i checked i have normal heat. Any help would be great!!

Thanks so far for all of your help...

 

Everyone have a safe Happy Easter!!!!!

Leonard :D

 

 

Yes there are two coolant sensors. The sensor with the two wires is for the computer and the sensor with a single wire (located below/behind the AC compressor) is for the gauge cluster.

 

The relays do go bad and will usually go bad way before the coolant sensor. The relay has a lot of amps going thru it and the contacts will "wear out".

 

The manual switch is not OEM and may suggest as Barry mentioned that the computer has been changed to a non Shelby Dakota computer. A simple way to check for a computer change is to look at the tachometer, does it work?

 

Steve

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Thanks Steve and yes the tachometer does work. When i got the truck i noticed there was 1 screw missing that holds the brain box to the passenger side inner fender skirt luckily i had an exact screw in my nut/bolt tray and replaced the missing screw. So what your saying is facing the relays from the drivers side fender looking down the very- 1st one is the bosh driving lights relay- 2nd the fan relay- 3rd the shutdown relay- 4th is the ac/clutch relay and- 5th (the silver long relay is the starter relay) correct?

 

Please e-mail me as soon as you can to confirm... :D

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I thought i would post this NAPA Auto Parts has the fan relays for our Shelby Dakota's the part is # AR630 it doesn't have a ridge on one side like our relay plug has. You need to trim off the ridge of our old plug with a dremel or whatever you have. Be careful not to damage the plug. Once the ridge has been shaved off the new relay slides right in. Our old relay has been changed to the new one without the ridge. My old relay had a burnt connector which the manager said is common with age. I wanted to ask this question- Should i replace the 2 wire coolant temp sensor also as a good measure or leave it alone? Thanks for all of your help. :D Have a Great weekend!!!

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I thought i would post this NAPA Auto Parts has the fan relays for our Shelby Dakota's the part is # AR630 it doesn't have a ridge on one side like our relay plug has. You need to trim off the ridge of our old plug with a dremel or whatever you have. Be careful not to damage the plug. Once the ridge has been shaved off the new relay slides right in. Our old relay has been changed to the new one without the ridge. My old relay had a burnt connector which the manager said is common with age. I wanted to ask this question- Should i replace the 2 wire coolant temp sensor also as a good measure or leave it alone? Thanks for all of your help. :D Have a Great weekend!!!

 

Those coolant sensors are pretty simple and either work or don't work so might as well leave it be.

 

Steve

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I wont be much help on this thread but I thought I would chime in and say that if you run your a/c that the fan will run non stop

 

 

 

:) I just replaced the fan switch relay and the 2 wire engine coolant temp sensor <-(my mechanic suggested) I can't get the a/c fan to kick in when the a/c is activated. The engine fan still won't kick in either. I tested both the fans again with jumper wires straight to the battery and they both work. Are there any suggestions on how to solve this issue? Should i hookup an auxilary adjustable thermostat with sensor ( about $40.00 ) to the battery and adjust it accordingly to come on at about 1/4 the way up the temperture gauge or keep trouble shooting this problem?

The tachometer does work in this truck... Sorry to be a bother with this problem... Thanks to everyone that has posted so far to help it has been greatly appreciated. Leonard Warner- Have a great weekend !!

:D

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:) I just replaced the fan switch relay and the 2 wire engine coolant temp sensor <-(my mechanic suggested) I can't get the a/c fan to kick in when the a/c is activated. The engine fan still won't kick in either. I tested both the fans again with jumper wires straight to the battery and they both work. Are there any suggestions on how to solve this issue? Should i hookup an auxilary adjustable thermostat with sensor ( about $40.00 ) to the battery and adjust it accordingly to come on at about 1/4 the way up the temperture gauge or keep trouble shooting this problem?

The tachometer does work in this truck... Sorry to be a bother with this problem... Thanks to everyone that has posted so far to help it has been greatly appreciated. Leonard Warner- Have a great weekend !!

:D

 

 

Leonard

 

The Shelby Dakota uses two fans in tandem meaning that there is no separate a/c fan like some vehicles have. So if the fans are needed for the a/c or because of engine temps both fans will turn on.

 

You say the fans don't turn on when you activate the a/c, keep in mind that the a/c system must be charged with freon for the fans to turn on in the a/c mode. There is a low pressure switch that prevents the fans or the a/c clutch from being activated when the freon is low. Just something to keep in mind.

 

The easiest fan, relay, wiring test you can perform is to disconect the two wire connecor from the temp sending unit. This will turn on the fans non-stop. If you disconect this connector and the fans don't turn on, by the way make sure the engine is running when you try this, there is a problem with the wiring and or relay.

 

And yes you can bypass the factory wiring by installing an aftermarket adjustable fan relay/switch. If you do go this route make sure you connect the a/c wire from this aftermarket switch. You can damage the a/c system if this wire is not hooked up.

 

I do have concerns with that relay you "modified to fit". The OEM relay is not anything special and should be available so there is no need to purchase an incorrect relay thats doesn't plug in.

 

Since you know the fans work that only leaves wiring or the relay. I say take another look at the relay.

 

Steve

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Leonard

 

The Shelby Dakota uses two fans in tandem meaning that there is no separate a/c fan like some vehicles have. So if the fans are needed for the a/c or because of engine temps both fans will turn on.

 

You say the fans don't turn on when you activate the a/c, keep in mind that the a/c system must be charged with freon for the fans to turn on in the a/c mode. There is a low pressure switch that prevents the fans or the a/c clutch from being activated when the freon is low. Just something to keep in mind.

 

The easiest fan, relay, wiring test you can perform is to disconect the two wire connecor from the temp sending unit. This will turn on the fans non-stop. If you disconect this connector and the fans don't turn on, by the way make sure the engine is running when you try this, there is a problem with the wiring and or relay.

 

And yes you can bypass the factory wiring by installing an aftermarket adjustable fan relay/switch. If you do go this route make sure you connect the a/c wire from this aftermarket switch. You can damage the a/c system if this wire is not hooked up.

 

I do have concerns with that relay you "modified to fit". The OEM relay is not anything special and should be available so there is no need to purchase an incorrect relay thats doesn't plug in.

 

Since you know the fans work that only leaves wiring or the relay. I say take another look at the relay.

 

Steve

 

 

 

 

Hey Steve i noticed from a earlier post that there are 2 relays in the group of 3 the first one is the fan relay the 2nd is the auto shut off relay the 3rd is the ac/ relay. I wanted to ask you this also i used to keep the battery unhooked while restoring the inside so it wouldn't drain the battery down like it did before right after i got the truck i wonder if leaving the battery unhooked and finally hooking it back up again if the computer and the electronic system had to reset itself. Now when i start the truck and turn the a/c on (truck is cold) while facing the truck the left fan comes on and off like it's supposed to. I presume that's the a/c fan the right one didn't come on of course the truck was cold and hadn't warmed up yet. I will preform more tests this weekend.

I went to the dealership to get the right relay first with no luck they said it was discontinued then i went to autozone ,advance auto parts ,carquest, O'Reilly with no luck then the dealership said go to NAPA . NAPA had the exact picture of the relay and ordered it when it came in it didn't have the ridge on it the NAPA manager called their supplier and told us it had been changed to the one without the ridge on one side . That's why i posted the earlier post about trimming off the ridge on the factory plug to accept the AR 630 relay. Looking under the relay at the numbers on each contact terminal they are the same and it also is a 30 amp relay. I will start the truck this weekend and let it get warm enough to see if the right fan engages hopefully it will engage before the temp gauge goes over halfway. If there is any more input to help please post i check back daily

Thanks again Steve and everyone.

Leonard-posted on 04-24-10

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Hey Steve i noticed from a earlier post that there are 2 relays in the group of 3 the first one is the fan relay the 2nd is the auto shut off relay the 3rd is the ac/ relay.

The a/c relay is for the compressor clutch control. The fan relay and the a/c clutch relay are wired (and controlled by the ecu) in such a way that the fan will come on purely under ecu control (temperature) as long as the a/c is not on. But turning on the a/c should make the fans run all the time (as long as there isn't another problem with the a/c, as Steve pointed out).

 

Now when i start the truck and turn the a/c on (truck is cold) while facing the truck the left fan comes on and off like it's supposed to. I presume that's the a/c fan the right one didn't come on of course the truck was cold and hadn't warmed up yet.
As Steve said in his post, the fans are wired in tandem, meaning they both should run when the fan relay supplies the power. If you have only one fan running, then either someone tampered with the way they are wired or you have a bad fan motor.
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The a/c relay is for the compressor clutch control. The fan relay and the a/c clutch relay are wired (and controlled by the ecu) in such a way that the fan will come on purely under ecu control (temperature) as long as the a/c is not on. But turning on the a/c should make the fans run all the time (as long as there isn't another problem with the a/c, as Steve pointed out).

 

As Steve said in his post, the fans are wired in tandem, meaning they both should run when the fan relay supplies the power. If you have only one fan running, then either someone tampered with the way they are wired or you have a bad fan motor.

 

 

 

I'm trying hard to understand this as you can see it's a confusing situation. When i test drove this truck and the 2 to 3 weeks after i bought it the outside temps were 36 degrees and under the fan came on all the time when the temp gauge hit 1/4 of the way up an the temp gauge would drop quickly down to the bottom. It was only after the outside temps were above 60 degrees i had an overheat problem starting and the fan didn't come on enough.

I apologize for all this agravation. I'm not very good figuring out electrical problems I'm trying everyone. Please be patient with me. I'm pretty much all alone out here in N.C.

 

SDAC guy the fan motors do work great. I will do the test tomorrow (sunday) and let the truck warm up and see if the fans coroporate or not and post my findings. When i turn on the a/c (truck cold)the passenger side fan kicks on an off like normal. Enjoy the rest of your weekend :)

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I'm trying hard to understand this as you can see it's a confusing situation. When i test drove this truck and the 2 to 3 weeks after i bought it the outside temps were 36 degrees and under the fan came on all the time when the temp gauge hit 1/4 of the way up an the temp gauge would drop quickly down to the bottom. It was only after the outside temps were above 60 degrees i had an overheat problem starting and the fan didn't come on enough.

I apologize for all this agravation. I'm not very good figuring out electrical problems I'm trying everyone. Please be patient with me. I'm pretty much all alone out here in N.C.

 

SDAC guy the fan motors do work great. I will do the test tomorrow (sunday) and let the truck warm up and see if the fans coroporate or not and post my findings. When i turn on the a/c (truck cold)the passenger side fan kicks on an off like normal. Enjoy the rest of your weekend :)

 

 

 

Leonard you must remember the two electric fans always run together at the same time. They are NOT separate fans, they will always run together for cooling the truck or drawing air across the a/c condensor when the a/c is activated.

 

If only one fans runs then you have a wiring problem or a fan motor that has gone bad or is going bad. A bad relay or ECM will cause the fans to not work at all so since you say one fan is working then the relay and ECM appear to be fine.

 

With the truck running at idle go and disconnect the two wire coolant sensor near the thermostat housing. Both fans should come on and stay on until you plug the connector back in. If this does not happen you have a wiring and or fan motor problem.

 

Steve

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Leonard you must remember the two electric fans always run together at the same time. They are NOT separate fans, they will always run together for cooling the truck or drawing air across the a/c condensor when the a/c is activated.

 

If only one fans runs then you have a wiring problem or a fan motor that has gone bad or is going bad. A bad relay or ECM will cause the fans to not work at all so since you say one fan is working then the relay and ECM appear to be fine.

 

With the truck running at idle go and disconnect the two wire coolant sensor near the thermostat housing. Both fans should come on and stay on until you plug the connector back in. If this does not happen you have a wiring and or fan motor problem.

 

Steve

 

This kind of makes sense why the truck only started to over heat once the ambient temperature rose. 1 fan works, 1 doesn't.

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This kind of makes sense why the truck only started to over heat once the ambient temperature rose. 1 fan works, 1 doesn't.

 

 

Hey Steve congrats to you and everyone else for your input: I ran a couple of tests : (truck is cold) #1 i unhooked the temp two wire sensor and the passenger side fan came on of course with it running. #2 I ran jumpers again to the drivers side fan to the battery it ran great! I noticed the passenger side fan would stop then i held the connector and it started up again so it seemed loose inside not keeping the connection like it should (of course not trustworthy).

Should i make a 3 to 4 inch Y adapter with female slide in connectors and hook both fans to a auxilary adjustable thermostat control with relay?

Or cut the male slide in connectors off of the fans (nervous about this being it's factory but will do to solve this issue) and make a 3 to 4 inch Y adapter but without the male and female slide in connectors (basically eliminating the possibility of the fan male connectors also not getting the connection good enough?

Please reply when you all can always checking: Thanks to everyone again for your help. :-)

Leonard

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This kind of makes sense why the truck only started to over heat once the ambient temperature rose. 1 fan works, 1 doesn't.

 

 

Hey Steve congrats to you and everyone else for your input: I ran a couple of tests : (truck is cold) #1 i unhooked the temp two wire sensor and the passenger side fan came on of course with it running. #2 I ran jumpers again to the drivers side fan to the battery it ran great! I noticed the passenger side fan would stop then i held the connector and it started up again so it seemed loose inside not keeping the connection like it should (of course not trustworthy).

Should i make a 3 to 4 inch Y adapter with female slide in connectors and hook both fans to a auxilary adjustable thermostat control with relay?

Or cut the male slide in connectors off of the fans (nervous about this being it's factory but will do to solve this issue) and make a 3 to 4 inch Y adapter but without the male and female slide in connectors (basically eliminating the possibility of the fan male connectors also not getting the connection good enough?

Please reply when you all can always checking: Thanks to everyone again for your help. :-)

Leonard

 

 

 

 

Leonard

 

If your connectors have the typical corroding, as shown in the photo below, I would just clean the terminals up. Yes you can cut off the oem connectors but whatever you do don't just use some cheap crimp connectors. Those cheap no-name crimp connectors wont last with the amps that the fans pull thru them.

 

Keep in mind that the factory connectors, like shown in the pic below, were held together with ty-wraps once connected to the wiring harness connector. Also if you do decide to clean the factory terminals make sure you apply a dab of dielectric grease to the terminals to prevent future corrosion.

 

Steve

Dsc02362a.jpg

Dsc02362a.jpg

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ame='Phatnlow' date='27 April 2010 - 02:37 PM' timestamp='1272404250' post='956818']

 

 

 

 

Leonard

 

If your connectors have the typical corroding, as shown in the photo below, I would just clean the terminals up. Yes you can cut off the oem connectors but whatever you do don't just use some cheap crimp connectors. Those cheap no-name crimp connectors wont last with the amps that the fans pull thru them.

 

Keep in mind that the factory connectors, like shown in the pic below, were held together with ty-wraps once connected to the wiring harness connector. Also if you do decide to clean the factory terminals make sure you apply a dab of dielectric grease to the terminals to prevent future corrosion.

 

Steve

 

 

 

Hey Steve gm and thanks for telling me not to use those cheap no name crimp connectors. I didn't know they could not handle the amps going thru them. Mine do have some corrosion I tried to clean 2 of them (the passenger side fan) with a small wire brush and a very small flat bit screwdriver. I thought about getting the same gauge wire and soldiering them together and use heat shrink tubing to make the Y adapters once the oem plugs were removed. Is there any way to disassemble the oem connectors (like car stereo plugs) to clean them better more easily? Or do you kno w a better way to make a Y adapter minus the oem connectors?

 

Also can the ($16.99 like Autozone's for example) auxilary adjustable thermostat- relay handle the two fans in tandem

and on your temp gauge where does it usually go to when the fans are first activated and maintain the temp?

Like 1/4 of the way up or halfway up the gauge?

Leonard

 

Sorry to bother everyone with multi questions. I was always told if you have any uncertainties or doubts ask. Autozone told me to purchase 2 adjustable thermostats because one would not last very long under a 2 fan hookup. I cleaned the connectors with the right cleaner but still not getting a connection like it should be. Autozone told me over time the connecors get hot and spread losing their connectivity and become loose. I hope everyone is enjoying their weekend. Thanks again for your posts. Leonard

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  • 2 weeks later...

Scratch my last post, I guess it wasn't worthy of a reply. I met a guy last tuesday that has a team shelby windshield banner on his dodge charger. I registered my shelby dakota #995 about 3 months ago on a dodge shelby site but it hasn't been added yet. I go back and check often. How do i add mine here to team shelby? I guess i need to register mine here somehow.

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