Cooling fan wont come on
#1
Senior Member
Thread Starter
Cooling fan wont come on
A while back my car got hot. I found that the cooling fan wasnt coming on. I was checking the fan switch that screws into the block and noticed that the plug was in really bad condition. I soldered on a new pigtail and hoped that would correct the issue. It didnt. The fan DOES work when the a/c is turned on. So i dont believe the fan is the issue nor the fan switch in the block. That only leaves the wire itself and the relay correct? I read that its common for the relays to burn out. My question is would the fan still oporate when the a/ c is switched on if the relay was bad?
#2
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Re: Cooling fan wont come on
A while back my car got hot. I found that the cooling fan wasnt coming on. I was checking the fan switch that screws into the block and noticed that the plug was in really bad condition. I soldered on a new pigtail and hoped that would correct the issue. It didnt. The fan DOES work when the a/c is turned on. So i dont believe the fan is the issue nor the fan switch in the block. That only leaves the wire itself and the relay correct? I read that its common for the relays to burn out. My question is would the fan still oporate when the a/ c is switched on if the relay was bad?
1. With a fused jumper wire between RED wire & BLK/RED wire of the relay connector did the fan come on?
IF yes to # 1
2. Ground the fan switch connector, did the fan come on?
IF yes to # 2
break out the infrared temp gun and make sure it's truly hot enough to activate the fan switch. Mine doesn't kick on until about 235ish...
#3
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Join Date: Feb 2019
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Car: 1989 Trans Am
Engine: sp357
Transmission: T-5
Re: Cooling fan wont come on
I could be wrong but I think the fan temp switch in the head has no effect on whether or not the fan comes on when you turn on the air conditioning.
Put the key in the RUN (don't start the car) and run a wire from the temperature fan switch plug to a ground and see if the fan comes on. If it does then the temp switch could be bad. If it doesn't come on then you should start checking the relay.
*edit*
beat by 92RS
Put the key in the RUN (don't start the car) and run a wire from the temperature fan switch plug to a ground and see if the fan comes on. If it does then the temp switch could be bad. If it doesn't come on then you should start checking the relay.
*edit*
beat by 92RS
#4
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Re: Cooling fan wont come on
Define hot? Stock turn on temp is something like 220-230*. With the exception of idling in bumper to bumper traffic in summer heat or exceptionally slow drive-thru lanes, I seldom hear the fans kick in. 99% of the time the car is moving and the airdam handles the air flow through the radiator.
#5
Senior Member
Thread Starter
Re: Cooling fan wont come on
Define hot? Stock turn on temp is something like 220-230*. With the exception of idling in bumper to bumper traffic in summer heat or exceptionally slow drive-thru lanes, I seldom hear the fans kick in. 99% of the time the car is moving and the airdam handles the air flow through the radiator.
#6
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Re: Cooling fan wont come on
1. With a fused jumper wire between RED wire & BLK/RED wire of the relay connector did the fan come on?
IF yes to # 1
2. Ground the fan switch connector, did the fan come on?
IF yes to # 2
Replace the Fan Switch
#7
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Car: 92 Camaro RS
Engine: LO3
Transmission: T5
Axle/Gears: stock
Re: Cooling fan wont come on
The fact that the fan turns with the AC tells you that the relay and fan are good. The AC control sends a negative ground to the same green with white stripe wire that the fan switch goes to. You need to test to see if you have continuity from the connector at the fan switch to where it connects to the fan relay. If you do and grounding that connector with key on turns on the fan then the fan switch is defective. There aren't that many parts to this for it to be complicated. Check these things
Also should unplug the fan relay and check for any less than good connections there
Also should unplug the fan relay and check for any less than good connections there
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#8
Senior Member
Thread Starter
Re: Cooling fan wont come on
Was the 250 measured w/ a infrared temp gun? What happened to the actual troubleshooting procedures myself and other members pointed out, completely disregarded?
1. With a fused jumper wire between RED wire & BLK/RED wire of the relay connector did the fan come on?
IF yes to # 1
2. Ground the fan switch connector, did the fan come on?
IF yes to # 2
Replace the Fan Switch
1. With a fused jumper wire between RED wire & BLK/RED wire of the relay connector did the fan come on?
IF yes to # 1
2. Ground the fan switch connector, did the fan come on?
IF yes to # 2
Replace the Fan Switch
no I was using the temp gauge .i don't own an infrared gun. the car was acting like it was overheating. I wouldn't swear to the accuracy of the stock gauge but you can tell when they are running hot. I haven't disregarded and of this advice. Im still working on it. I feel like I will be able to get to the bottom of it and correct it with all of the suggested diagnostics offered.
#9
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Re: Cooling fan wont come on
no I was using the temp gauge .i don't own an infrared gun. the car was acting like it was overheating. I wouldn't swear to the accuracy of the stock gauge but you can tell when they are running hot. I haven't disregarded and of this advice. Im still working on it. I feel like I will be able to get to the bottom of it and correct it with all of the suggested diagnostics offered.
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