86 cooling fan relay
Thread Starter
Instructor
Joined: Apr 2003
Posts: 221
Likes: 0
From: midwest Iowa
86 cooling fan relay
Hi I have this 1986 vette I bought a upgrade kit for the cooling fan. But I for some reason keep blowing the fuse in the fuse block any one know or had this problem I havent driven this vette at all this year because of this any help would be great thanks
Burning Brakes
Joined: Jan 2007
Posts: 921
Likes: 0
From: Houston TX
A couple of ideas,
First, was it blowing fuses before you installed this "upgrade kit"? If not, go back over your work.
Second, get an ohmmeter and see if the "hot" side of the circuit is grounded to the frame. If so, look for a pinched or frayed wire.
Also make sure you have the correct amp fuse as that motors gonna draw some juice.
First, was it blowing fuses before you installed this "upgrade kit"? If not, go back over your work.
Second, get an ohmmeter and see if the "hot" side of the circuit is grounded to the frame. If so, look for a pinched or frayed wire.
Also make sure you have the correct amp fuse as that motors gonna draw some juice.
Thread Starter
Instructor
Joined: Apr 2003
Posts: 221
Likes: 0
From: midwest Iowa
I have checked the wiring I have a green wire that I guess it comes from the ECM then there is a black that looks like it has a red stripe on it that looks like it goes to the fan and a blue wire that is hot when I turn on the key and a red wire that is hot all the time. does this all sound good to you guys
Melting Slicks
Joined: Nov 2005
Posts: 2,736
Likes: 0
From: WAY UPSTATE NY
Wire colors sound correct. Check the black/red for a short to ground.
Does the fan run if you apply 12 volts directly to it? If you have the relay wired correctly and there is no shorts to ground I suspect that you have a bad fan motor
Does the fan run if you apply 12 volts directly to it? If you have the relay wired correctly and there is no shorts to ground I suspect that you have a bad fan motor
Team Owner
Joined: Jan 2003
Posts: 20,306
Likes: 242
From: Summerland B.C. Canada
Check your wiring, the fuse which you are blowing, only needs to supply 12 volts to the coil in relay. Maybe your wiring has it supplying 12 volts to the fan output from relay.
http://members.shaw.ca/corvette86/Co...%20Control.pdf
http://members.shaw.ca/corvette86/Co...%20Control.pdf
Thread Starter
Instructor
Joined: Apr 2003
Posts: 221
Likes: 0
From: midwest Iowa
Hi
I will Check the wires agian and make sure they are not shorted out I think I have an extra fan I think I will put it on and try that I am not wanting to drive it very far do to this problem. Thanks agian everyone for the help
I will Check the wires agian and make sure they are not shorted out I think I have an extra fan I think I will put it on and try that I am not wanting to drive it very far do to this problem. Thanks agian everyone for the help
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
upgrade kit
just what is included in this upgrade kit?
is it relays? fan and wires? what are you actually installing?
I added a relay, and an aux fan to my 86, and tied the fan positive wire to the relay coil positive. Then grounded the negative side of the relay coil. Now when the big fan comes on, the fan voltage energizes the coil to the aux fan relay, and the aux fan comes on at the same time. The fans don't energize over 35 mph, and the ecm doesn't see a load any different from the load it ususally sees because the coil ohms is 300 ohms, which is about a 1/4 of a amp. The load is from the battery terminal connector located ehind the battery, and is directly fed from the battery, not the alternator.
The alternator ultimately powers the fan, but indirectly, so the load isn't imposed immediately on the alternator. Just a few milliseconds later.
I am thinking of reverting back to the factory wiring of this fan, since I have a 200 degree switch from an 87 buick grand national to replace the factory one that's located in the front of the left head.
is it relays? fan and wires? what are you actually installing?
I added a relay, and an aux fan to my 86, and tied the fan positive wire to the relay coil positive. Then grounded the negative side of the relay coil. Now when the big fan comes on, the fan voltage energizes the coil to the aux fan relay, and the aux fan comes on at the same time. The fans don't energize over 35 mph, and the ecm doesn't see a load any different from the load it ususally sees because the coil ohms is 300 ohms, which is about a 1/4 of a amp. The load is from the battery terminal connector located ehind the battery, and is directly fed from the battery, not the alternator.
The alternator ultimately powers the fan, but indirectly, so the load isn't imposed immediately on the alternator. Just a few milliseconds later.
I am thinking of reverting back to the factory wiring of this fan, since I have a 200 degree switch from an 87 buick grand national to replace the factory one that's located in the front of the left head.
Last edited by coupeguy2001; Aug 11, 2007 at 01:57 AM.
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Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
I have checked the wiring I have a green wire that I guess it comes from the ECM then there is a black that looks like it has a red stripe on it that looks like it goes to the fan and a blue wire that is hot when I turn on the key and a red wire that is hot all the time. does this all sound good to you guys
What "upgrade kit" are you referring to? What does it consist of? Are you talking about a low temp fan switch like this?
http://www.mamotorworks.com/corvette?frame=3.944
Thread Starter
Instructor
Joined: Apr 2003
Posts: 221
Likes: 0
From: midwest Iowa
Hi agian And thanks to all for the help.
We took the Corvette out I noticed that the temp was climbing to 230 NO fan so I pulled over and shut motor off open hood and the wire that feeds the relay HOT all the time it has a 10amp fuse init was all melted. so I looked arond and there was a circutcity stereo store so I went over to them the install dept and beged for piece of wire so I could jumper the relay so when I turn the key the fan runs it got us home. I have sence bought a new relay and also bought a manul switch that I can turn on 1 or both fans .I would just like the relay to do its JOB. thanks
We took the Corvette out I noticed that the temp was climbing to 230 NO fan so I pulled over and shut motor off open hood and the wire that feeds the relay HOT all the time it has a 10amp fuse init was all melted. so I looked arond and there was a circutcity stereo store so I went over to them the install dept and beged for piece of wire so I could jumper the relay so when I turn the key the fan runs it got us home. I have sence bought a new relay and also bought a manul switch that I can turn on 1 or both fans .I would just like the relay to do its JOB. thanks
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
relay
I have an 86, and there's no fuse out there under the hood for it.
If you added the fuse, it should protect the fan motor hot side, as the coil windings will just burn up without a fuse, cause they are such small wires.
If that fuse was melted, and it got hot, you need to determine that the connections are good. A high current will just blow the fuse, but bad connections will melt stuff all the time.
I did add the aux fan out of an 85, and where the battery aux wire goes to that one wire connection junction is where I added my fuse to power the fan.
I did take the aux. fan relay coil wire and add it to the main fan power so that when the big fan comes on, the little fan will too.
The problem I get, is that with both fans running, it picks up so much more trash and dust, and throws it at the engine and the radiator.
If you added the fuse, it should protect the fan motor hot side, as the coil windings will just burn up without a fuse, cause they are such small wires.
If that fuse was melted, and it got hot, you need to determine that the connections are good. A high current will just blow the fuse, but bad connections will melt stuff all the time.
I did add the aux fan out of an 85, and where the battery aux wire goes to that one wire connection junction is where I added my fuse to power the fan.
I did take the aux. fan relay coil wire and add it to the main fan power so that when the big fan comes on, the little fan will too.
The problem I get, is that with both fans running, it picks up so much more trash and dust, and throws it at the engine and the radiator.
