Car is a 1992 z28 that has the 2 fan set-up. Neither fan will come on. I'm running a Hypertec fan switch and a 180 degree thermostat. I grounded the gray wire from the fan switch that is in the pass. head-did not come on. I then probed my relays while car was running and I had relay switches out. I got both fans to come on by touching the right wires. What is the deal? Is the fan switch bad?

 

If you disconnected the wire from the fan switch and grounded it, and the fans did not come on, then the wire is broken somewhere between the relays and the switch.

 

Now you know the wires are good from the relay to the fans. Do you have a multimeter? Can check for continuty to the fan switch and if the circut is closed when it reaches temp. If it is then the relay is the problem. Otherwise the fan sw.

 

I grounded my fan switch plug (small gray wire) and you could hear the relay click but the fan would not come on. There are three relays over by the brake booster, one for each fan and I assume the other is for the fuel pump. Is this right? Anyway it was my understanding that on the relay plugs for the fans, the fat orange wire should show twelve volts with the key off, mines not. Is the orange wire supposed to show twelve volts with the key off? I also did a test on the small gray wire between the switch plug and the relay plug and it showed the wire was not broken.

 

Yes, the orange fat wire is battery hot. Does it go high with ignition on?

https://www.thirdgen.org/techbb2/sho...hreadid=283556

Read the last post in the thread.

 

Both of my fat orange are not showing any power, with key on or off.

 

Update: I changed the 2 relays, the fan switch, and the CTS sensor, took the car for a ride, fans still didn't come on. I checked my relay plugs after I test drove the car and I did have power to the orange wires with the key off. I touched the 2 fat wires on each plug like you said in the thread and they didn't come on. I did however touch a small brown wire to the fat black with red stripe wire and the fan comes on.

 

Well, that sucks. The orange wire is connected to a fusible link which is right off of the battery. On your positive terminal, there are 2 wires. The big fat wire which goes to the starter and has other terminals off of the starter, and a little wire which goes to a fusible link which then goes to a junction.

One of those is to the fan relays. I don't know which, off hand. The fusible link may be shot. Check that first.

 

The big 2 wire plug coming off my positive post (Orange and red wires) is where I found that fusible link. The plug had a bad spot on it, on the orange wire side, where it looked as though it had gotten pretty warm. I cut it and put a new end on it and now I'm getting 13 volts at both of my relay plugs orange wires. I checked for continuity and both checked good. Took the car for a spin to warm it up and still no fans coming on. I'm about to get ill about the whole deal, but I know if I just keep chipping away at it, I'll figure it out. Auto electronics is not one of my strong points, as you can tell. I do however salute you for walking me through this deal. You are a big help. Thanks