86 c fan constantly running - Problem found
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 833
Likes: 1
86 c fan constantly running - Problem found
Ok guys, prepare yourselves for this appalling mess. On my 86, the cooling fan constantly runs. The problem is...well, complicated. There is a wire tied into the red and black wire that goes to the cooling fan motor. It is coming from the wiper fuse. (weird, right?) And the red wire that's supposed to go to a fusible link goes to the battery, instead. There is also a green wire that goes to the battery. I don't know what this is, but I'll check tomorrow. I hope it's not the one that goes to the ECM!
Drifting
Joined: Aug 2006
Posts: 1,624
Likes: 2
From: Canandaigua New York
Sounds like someone added the wire to make the fan come on.
Probably didn't know where to look for the problem, or 'thought' the engine temperature was too high so just connected it to a hot spot.
My old 84 was setup the same way. Wired to the hot side of the wiper motor.
There's quite a few threads on here from people asking about engine temperature and thinking it's too high.
Remove the wire going to the wiper and replace the fusible link for the red wire.
Then check to see if the fan comes on when it reaches temperature. I'm betting it does.
What side of the battery is the green wire connected to? + or - ?
And where does it run to?
Probably didn't know where to look for the problem, or 'thought' the engine temperature was too high so just connected it to a hot spot.
My old 84 was setup the same way. Wired to the hot side of the wiper motor.
There's quite a few threads on here from people asking about engine temperature and thinking it's too high.
Remove the wire going to the wiper and replace the fusible link for the red wire.
Then check to see if the fan comes on when it reaches temperature. I'm betting it does.
What side of the battery is the green wire connected to? + or - ?
And where does it run to?
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 833
Likes: 1
It's connected to the positive side, and I have no idea where it goes. I'm not even sure if it has anything to do with the fan. Like I said, I'll check that tomorrow.
My theory was that the fan relay wasn't working properly and they just bypassed it by using this method.
Mine isn't coming from the wiper motor, it's coming from the wiper fuse in the fuse box.
What is a fusible link?
My theory was that the fan relay wasn't working properly and they just bypassed it by using this method.
Mine isn't coming from the wiper motor, it's coming from the wiper fuse in the fuse box.
What is a fusible link?
Race Director
Joined: Feb 2004
Posts: 12,518
Likes: 19
It's connected to the positive side, and I have no idea where it goes. I'm not even sure if it has anything to do with the fan. Like I said, I'll check that tomorrow.
My theory was that the fan relay wasn't working properly and they just bypassed it by using this method.
Mine isn't coming from the wiper motor, it's coming from the wiper fuse in the fuse box.
What is a fusible link?
My theory was that the fan relay wasn't working properly and they just bypassed it by using this method.
Mine isn't coming from the wiper motor, it's coming from the wiper fuse in the fuse box.
What is a fusible link?
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
By always hot, they mean it has 12v on it all the time. BTW your title is incorrect, no description of finding the reason why your fan runs continuously.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You said the fan motor runs continuously. If the fan motor was wired to the wiper fuse, then the fan motor can only run when the ign sw is in accy or run position. With the ign sw in any other position, the fan motor will not run. My statement is correct, you did not find out why the fan runs continuously.
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Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 833
Likes: 1
You said the fan motor runs continuously. If the fan motor was wired to the wiper fuse, then the fan motor can only run when the ign sw is in accy or run position.
You said it yourself, why are you doing this? If you're to gonna post anything productive then just leave.
You said it yourself, why are you doing this? If you're to gonna post anything productive then just leave.
Last edited by tehcarguy; Oct 3, 2010 at 01:10 AM.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You said the fan motor runs continuously. If the fan motor was wired to the wiper fuse, then the fan motor can only run when the ign sw is in accy or run position.
You said it yourself, why are you doing this? If you're to gonna post anything productive then just leave.
You said it yourself, why are you doing this? If you're to gonna post anything productive then just leave.
I come to this forum to help people and I read posts when someone says they fixed something so I might learn too. Many posters here don't provide the year vette they are asking help for and some don't provide an accurate description of their problem and thus no one can help them. If you are angry at my posts, you should be angry with yourself, not me, YOU made the mistake.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
I guess I'm not average, because I know what, "continuously", means. If your fan runs continuously with the ign sw on, then say it that way, then no one has to be clairvoyant.
Race Director
Joined: Oct 2005
Posts: 11,770
Likes: 175
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
Have to agree with jfb on this one.
He is one of the best when it comes to helping people with electrical issues.
Don't be so quick to criticize what he says.
And I also thought when you said "continuously", it meant the fan was always running (even with the key off).
He is one of the best when it comes to helping people with electrical issues.
Don't be so quick to criticize what he says.
And I also thought when you said "continuously", it meant the fan was always running (even with the key off).
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Best thing to do here is move on.
Next best thing is remove all the wires that you think don't belong, obtain a wiring diagram, and use an ohm meter, and ohm out the circuit.
Buy a couple fusible links of the proper size, and be prepared to splice them in.
1. you know the fan works
2. probably the majority of the original wire is in the car and untouched, just cut
3. with any luck, you will have to splice in only one fusible link and splice 3 wires.
Next best thing is remove all the wires that you think don't belong, obtain a wiring diagram, and use an ohm meter, and ohm out the circuit.
Buy a couple fusible links of the proper size, and be prepared to splice them in.
1. you know the fan works
2. probably the majority of the original wire is in the car and untouched, just cut
3. with any luck, you will have to splice in only one fusible link and splice 3 wires.
Thread Starter
Burning Brakes
Joined: Aug 2010
Posts: 833
Likes: 1
My apologies to jfb, I had a few too many last night. I disconnected the wire that runs from the fuse box, and turned the ignition on and the fan didn't come one. But before letting the engine come up to temp to see if the fan comes on, I want to make that fusible link to be right. Is it supposed to be screwed on to the frame rail near the battery? I see a connector there with nothing attached to it.
