vantheman1976

Okay, so I will start at the beginning. I have a 1991 Z-28 350...the car was originally a 305 about 70,000 miles ago, until it was shot, then replaced with the 350. I began to have an overheating problem...checked everything out, and determined my issue was with the water pump. Changed out the water pump, also, since I was there, went ahead and changed the thermostat. Then, everything worked fine, for a shirt time...I had put a 170 deg thermo in it, and temp was kept down to a nice 170-180 deg. Then it started getting hot again...looked around, and I had a hole in the radiator...on the back end. This was caused by one of the cooling fans slapping the radiator. The lower bracket had broken for the fans, causing them to swing into the radiator....hey, at least the fans were running, right? Anyway, ordered the lower bracket from the dealer, and purchased a new radiator. I pulled the fans out, replaced the radiator and lower bracket, then reinstalled the fans. Then, the fans stopped working, both of them...a/c on, it doesn't matter, neither will run. Ran the car a few days like this because I didn't have to time to mess further, and the car was not overheating, it stayed nice and cool, because I wasn't spending a lot of time idleing. Then I got stuck it a bit of traffic, and the engine got a bit hot, ended up boiling out a little coolant. Stopped at the part store, let the engine cool, reserviced it up, and drove it back to the house, to which the engine stayed around 240 - 250 deg all the way to the house. So, I have proper servicing, the car still gets really hot while moving (yes, my dam is good to go), and the fans won't turn regardless. I am wanting to say the relays are bad, but isn't there a seperate relay for each fan? Would they both go bad at the same time? Also, not sure exactly where the relays are...so if anyone could guide me on that, it'd be really appreciated as well.

shanewbenson

you could just do what most do and wire in a manual switch for the fans (assuming they work. ) or just wire it so they run all the time.

vantheman1976

Okay, so I think I might have an issue with the fans themselves...I am getting voltage from the connector going to the secondary fan when I have the a/c turned on....

vantheman1976

Damn...did I jump the gun...I just did a voltage check on the other connector, and I am getting equal voltage from it as well, and the engine is not up to temp.

vantheman1976

Okay, so I fugured out the relay locations (I think) from trial and error. With the engine temp sufficient that both fans should be running, I rand a voltage check on the relay power wires with the relays out. I am getting pretty steady between 12 and 14. And of course, I am only getting .5 at the fan connectors. Also, one of the relays has a slight rattle if you shake it. So, replace relays?

vantheman1976

Also, just wired the fan motors directly to the battery and they both work.

shanewbenson

you can just splice a wire into the ground wire on the relay and connect it to the firewall. this will cause your relay to always be grounded and your fans will always run when the key is in the on position.

vantheman1976

Well, unfortunately, I wasn't able to get any troubleshooting advice here....more of a fan of figuring out what the problem is and fixing it, not just rigging someting up to get around the problem....no offense. But, I ultimately figured out part of the problem on my own...the fans not turning on...I troubleshot it down to either the relays or the wiring...changed the relays, no dice...then went through the wiring, and found a broken wire...need a new connector and stuff, but I got it wired around that to get the fans working so that I can get back and forth to the parts store.

Engine still seems to be running a bit hot though...sitting at idle (of course my idle is slightly high due to a vacuum leak that I still need to look into. But, once heated up, it'll idle at about 250...just a hair below the red. Haven't gotten it out on the road yet to see what happens, but this is where I am at right now.

b4ccamaro

Both of those fans are on totally diff circuits. The only things they have in common are the power wire and theground. They both share a fusible link at the starter that they get their power from. If they both died at the same time I would check that or check their ground. They both ground on the right hand side right in front of the battery on the core support. good luck