Need help with intrepid dual fan issue

[Cyclops389]

Okay guys I am about ready to pull my hair out. This is going to be long but I don't know what else to do at this point.

I have read all the topics I could find on the issue here with no luck on my issue.

87 Grand National with minimum info from previous owner so I'm learning the aftermarket stuff as I go.

2nd week I had it one of the dual fan motors fried. He had it hooked up with a basic plug and play 4" harness which after reading up I learned dual fans really need extra relays for this setup. The fans were older intrepid fans (pre 99 I assume due to the small motors) but one still worked when I parked it.

I replaced the fans with 99-2005 intrepid fans and a nice new caspers harness with relays. As I'm hooking up the fans I found the stock connector melted. I repaired this as best as possible and tried the fans. Nothing! So I ask around and get a few different answers but none that worked. So I ordered a new splice connector from Caspers to be sure I had a solid connection (I know I wasn't happy about cutting the wires but it was melted so I didn't really have a choice) and started it back up tonight. No go still.

I did speak with a nice gentleman tonight over the phone and he had me check a few things. One thing was the sensor in the intake under the throttle. I grounded this with the key on and heard the relay click but still no fan. In this process I did figure out what the little toggle switch in the center console was, this is to control the fan. So I switched it up and down through all three settings but still no fan.

Here is my dilemma. I'm not good with a multimeter but I pick things up pretty well. With having this manual switch I'm assuming somewhere in that line there is an issue but I'm at my wits end searching for it. This whole process has been going on for two solid weeks and I know it is something simple that I am over looking or can't see.

Sorry this is so long but I am just ready to drive my car and stop being so frustrated every afternoon when I get home. I will pay for someone to honestly help me through this as I know people's time is valuable.

Thanks for reading


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[TurboBuRick]

More than likely the ground is missing. Do you have a test light? Clamp the clip on the positive battery lead and check the ground wire to the fan.

 

[Cyclops389]

More than likely the ground is missing. Do you have a test light? Clamp the clip on the positive battery lead and check the ground wire to the fan.

Thanks I'll check that this afternoon


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[pacecarta]

i cut the dodge connector off and wire in a GM fan connector so it can connect to OE harness , the racetronix hotwire kit that used to be available provided new gm plug and terminals to be installed on the fan
the engine side plug to the fans has three terminals A,B and C
B and C are low and high relay outputs , and when relays are active the terminals should have power ,,check with a volt meter or test light
A is ground ,, make sure that has continuity with an ohm meter
if you have power at B or C and ground at A and no fan then fans are bad replace them

info on testing the oe fan system are here http://vortexbuicks-etc.com/fan.htm
how to test quickly ..key on
if you unplug the fan control switch plug from behind the a/c compressor there are three pins in the plug you can activate the fan relays by grounding the green terminals on the A/C fan control plug
you can use a short wire to ground the pin to the alternator case if you hear relay click you should have power at one of the fan terminals B or C
grounding the other green wire youll trigger the other relay and again a or B should show power ...
if relays dont click the issue is a bad relay or a blown rlys fuse under dash or a bad ground to the relay coil
if relays are clicking and you dont have power at B or C then the relay may be bad or the fusible links burned up down by the starter
you can pull the relay and check for the fan power at the large red wire

for what its worth using fans from junk yard isnt that good an idea because for some reason dodge ran the passenger side continuously by controlling the ground to the fans so its common for those passenger side motors to be worn out before the driver side

heres the fan diagram

 

[Cyclops389]

i cut the dodge connector off and wire in a GM fan connector so it can connect to OE harness , the racetronix hotwire kit that used to be available provided new gm plug and terminals to be installed on the fan
the engine side plug to the fans has three terminals A,B and C
B and C are low and high relay outputs , and when relays are active the terminals should have power ,,check with a volt meter or test light
A is ground ,, make sure that has continuity with an ohm meter
if you have power at B or C and ground at A and no fan then fans are bad replace them

info on testing the oe fan system are here http://vortexbuicks-etc.com/fan.htm
how to test quickly ..key on
if you unplug the fan control switch plug from behind the a/c compressor there are three pins in the plug you can activate the fan relays by grounding the green terminals on the A/C fan control plug
you can use a short wire to ground the pin to the alternator case if you hear relay click you should have power at one of the fan terminals B or C
grounding the other green wire youll trigger the other relay and again a or B should show power ...
if relays dont click the issue is a bad relay or a blown rlys fuse under dash or a bad ground to the relay coil
if relays are clicking and you dont have power at B or C then the relay may be bad or the fusible links burned up down by the starter
you can pull the relay and check for the fan power at the large red wire

for what its worth using fans from junk yard isnt that good an idea because for some reason dodge ran the passenger side continuously by controlling the ground to the fans so its common for those passenger side motors to be worn out before the driver side

heres the fan diagram

View attachment 307275

Thank you for the details! The fans are brand new they are just for the intrepid. This is perfect for me to run through tonight.


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[Cyclops389]

I have a good ground.


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[Cyclops389]

Both relays have a hot coming in but no hot at the factory connector at the fan.

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[Dhos1]

So, I just installed a intrepid set-up....sorry to hi-jack, but what's this extra relay hogwash that I may need????

 

[Cyclops389]

So, I just installed a intrepid set-up....sorry to hi-jack, but what's this extra relay hogwash that I may need????

From my understanding the stock relays won't hold the load of the dual fans. Caspers Electronics sells a nice harness for these fans.


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[Cyclops389]

i cut the dodge connector off and wire in a GM fan connector so it can connect to OE harness , the racetronix hotwire kit that used to be available provided new gm plug and terminals to be installed on the fan
the engine side plug to the fans has three terminals A,B and C
B and C are low and high relay outputs , and when relays are active the terminals should have power ,,check with a volt meter or test light
A is ground ,, make sure that has continuity with an ohm meter
if you have power at B or C and ground at A and no fan then fans are bad replace them

info on testing the oe fan system are here http://vortexbuicks-etc.com/fan.htm
how to test quickly ..key on
if you unplug the fan control switch plug from behind the a/c compressor there are three pins in the plug you can activate the fan relays by grounding the green terminals on the A/C fan control plug
you can use a short wire to ground the pin to the alternator case if you hear relay click you should have power at one of the fan terminals B or C
grounding the other green wire youll trigger the other relay and again a or B should show power ...
if relays dont click the issue is a bad relay or a blown rlys fuse under dash or a bad ground to the relay coil
if relays are clicking and you dont have power at B or C then the relay may be bad or the fusible links burned up down by the starter
you can pull the relay and check for the fan power at the large red wire

for what its worth using fans from junk yard isnt that good an idea because for some reason dodge ran the passenger side continuously by controlling the ground to the fans so its common for those passenger side motors to be worn out before the driver side

heres the fan diagram

View attachment 307275

Okay so here's what I've found...

The manual switch ties into the sensor at the AC line

So I pulled that out and bypassed it on both hots. Both relays are working up to that point. At the stock fan connector there is still no power. Scratching head waiting on further instructions lol


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[Dhos1]

Heck I just have a short harness about 4-5 inches. I need the longer one then....the one that includes the relays....damn, more money

 

[Cyclops389]

Heck I just have a short harness about 4-5 inches. I need the longer one then....the one that includes the relays....damn, more money

Yeah that's what was on this one and the reason I just went through two weeks of hell tracking down that it fried the relay and stock connector. Trust me spend the money and just do it right.


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[Cyclops389]

I want thank you guys for the help and Pacecarta for the very detailed check list!

She is back up and going now after finding the relay was toast.

Now I have a way better understanding of the wiring in that department so it wasn't all bad.


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[Cyclops389]

Okay guys I thought I had the issue fixed (and I kind of do) but I can jump the fans at the relay plug so I thought it was the relay but when I replaced the relays I still got nothing. I have two new relays on the harness at the fans. Is that the problem? Can using other sets of relays cause it not to work? If so how do I cleanly bypass the two stock relays?

They have a few wires coming into them so I don't want something not to work by doing away with them and I want a clean job.




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[pacecarta]

theres two power terminals at the relay plug ..one is from the fusible link (heavy red) and is power for the fan , the other power is red blk stripe light gauge wire for the relay coil

 

[Cyclops389]

theres two power terminals at the relay plug ..one is from the fusible link (heavy red) and is power for the fan , the other power is red blk stripe light gauge wire for the relay coil

So just cut them at the plug and run them direct?

Once again excuse my ignorance


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[pacecarta]

no ..look at the diagram and with a test light find out if you have main power and with key on if you have relay coil power ...if you dont ...fix it

 

[captndave737]

I don't mean to hijack the thread but If I understand it correctly the Intrepid fans have 2 sets of windings on each motor 1 or the other is energized for low speed and both energized for high speed. Is that correct?

I thought I had a Caspers Harness but now I'm not sure. My harness only uses the Low Speed fan relay output to energize the fields on BOTH the HD relays mounted on the radiator, which, if the above is correct my fans only operate on high. The power comes directly from the battery to the NO contacts of the fan relays the other end goes to ground.

So right now my stock high speed relay does nothing. I've already removed the fan delay relay. I'm trying to clean up the engine bay while the engine is out so I'm looking for suggestions. Should I?
A-remove the high speed fan relay and the associated wiring and always have the fans on high when they are operating or,
B- Rewire it so the Low Speed Relay energies the field of one Radiator mounted relay and one set of windings and have the High Speed relay energize the other Radiator mounted relays and the second set of windings?

 

[pacecarta]

yes both active for high and yes the caspers hotwire harness i have encountered had both fans in high with two relays both being controlled by the low relay on the fender and it did not use the OE high relay circuit so if you lost the low relay the fans would not come on at 224 because the OE high side relay would activate but arent connected to anything
that harness also used the crysler fan connector , with a little rewiring of one of the relay coil power wire in that harness you could make that hotwire run in low and high as the factory had it restoring the high relay operation ..in the north east we dont need hi mode all the time

 

[Cyclops389]

Turns out it was my fusible link. I couldn't see it the first time I looked till I got the car up a little higher.

It runs right across the top of the starter. It's crispy fried


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