Not getting much love in the cooling forum, so I figured I would post here.

I have dual electric fans, and they were working fine. I had an issue where the fan temp switch in the pass side head got melted from the heat from my new headers, so I got those replaced.

Before the issue, my main fan was running all of the time, now it wont turn on at all. My understanding is that the main fan should run in diagnostic mode (A/B Jumpered) as well as when the A/C is on, but neither is happening.

Because I think the fans are functional, where should I be looking? Could it be the fusable link from the positive feed on the battery cable? Could it be a relay?

I'm not sure where to start. Any guidance would be greatly appreciated.

 

My headers did the same to my sensor. All i did was run a switch to the battery and positive line on the fan and mouted it up in the car. So now my fan is on a switch. Its nice to be able to keep it on all the time if I feel the need to be running cool. Plus it allows you to run a 160* thermo which keeps you even cooler. Was a 2 hour project with 2 people and I mounted it under my light controls.

 

Im planning on putting a switch in, but still doesnt explain why my fans arent working now after I replaced that stuff.

Anyone have any ideas?

 

I used to have tha same problem on my1991 z28 camaro 305 tpi a year a go. I put the fan switch to the water pump. work very well

 

A switch does not fix the a problem you have, it merely hides one or more indicatons of a problem.

You can easily troubleshoot your fan wiring. You could find a bad relay or a frayed fried wire or something. You can start tracking the problem at the relays (engine compartment, on the firewall, driver side, by the brake booster). This diagram here should help: http://austinthirdgen.org/modules/Co...ine_wiring.gif

If you need different diagrams, look at our ATGO (AustinThirdGen.Org) diagram page, we have a lot of detailed ones for later years, tool. AustinThirdGen.Org » Content » Tech Articles » 3rd-gen wiring diagrams

Let us know what you find and if you need step by step instructions on how to troubleshoot the problem, do a search first on my posts and then feel free to post specific questions.

Lou

 

Thats the thing, I know theres a problem, so thats why I am trying to figure out where to start.

I have a multimeter, but Im not all that good at knowing what to do to test the electronics.

Where should I begin as far as trying to figure out if its a relay or the fusable link? or some other issue?

 

You can look at the schematic I posted above. The cooling fan relays are in the lower right corner. Find the colors of the wires and then find the right relay on the firewall. Probe the wires (the orange should have 12V at all times). The brown wire should have power with the key on. Ground the green/white wire (with the key on) to see if the fan turns on.

You should find at least two of the relays to be identical. Swap them. See if it makes a difference.

Get back to us with results.
Lou

 

OK Man, thats what i was looking for

I cant get back to work on the car this weekend, but i will post up results when I do.

 

Check all your fuses. The power source for the fans comes straight off the battery. Somehow my single pin connector melted one time and it lost power. Or just buy all new relays, they're like $7, there is one for the primary and one for the secondary, on my T/A they're on the Pass side inboard of the fender. They're cheap and go bad on occasion. Otherwise you will be chasing wires... make sure no wires have been burnt by the headers! To test for voltage, turn the dial to VDC or --- put the black lead on ground or negative (usually the bare frame or bare engine) and the red lead on the source. Follow the diagram above for where to check.

Please correct me if I'm wrong but the primary (drivers side) operates with the engine up to a certain vehicle speed and the secondary (pass side) operates when the AC is turned on or the fan switch sensor in the passenger side head reaches a certain temp... I think stock is 210* ?? Good luck!

 

I figured I would probably buy some new relays.

Which fuses are you referring to, the ones under the dash?

Also, is the power source for the fans the little red wire with the fusable link? Ive never really traced it out.

 

Yes, the fuse on the fender, with red and orange wire, that's the fuse for your fans and fuel pump. If this one is bad (or the wires), the car won't run and both fans won't work.

There is also a fuse under the dash, it's called FAN and it controls the relays for the fans. But again, if it's bad, neither fan will turn.

Lou