Was hoping to get a little help on a fan issue. I've gone through the basics I think and read 100 posts about it. Found a great troubleshooting guide someone posted but unfortunately it ended right before Chart 12-C, which was the one I needed. Anyway...

Changed the relays
manually put power to fans. They work
Checked under dash 20A fuse. Good
Wires all look intact.

Did diagnostic terminal ground test. No fan
Grounded the fan switch. Clicking relay, no fan
Tried turning on AC. No fan

The only thing that doesn't vibe with the schematic on the GM maintenance book that was posted is the orange wire that is supposed to go to the battery with a fusible link. There is no wire that goes from the relays to the battery.

The wires that go to the relays come from the firewall area on the passenger side and go into a cluster behind the engine.

There is one unidentified power wire at the battery but it goes toward the firewall on the drivers side and there isn't a fuse on that either. it's in the same cluster as the washer motor.

would the battery/fusible link wire normally go through the firewall and back to the battery? I just assumed it was more direct.

Thanks for any help.

 

Where are your fan relays? pass side core support by the rad and inner fender structure?

 

Passenger side. One on the rad mount and one on the other side of the canister.

 

a couple of pics that might help. Shows area around relays, where the wires leading to the relays come from and the ridiculous mess the PO made of the battery terminal. The wire with the yellow butt joint is the only one I don't know what does





Relays





Connector that joins relays, fans and wires from firewall.





Where wires originate from





Ugly battery terminal

 

The blower motor on the firewall is not part of the cooling system fans.

 

True. That pic was just to show where the wires from the relay came from. I found the problem. Thanks

 

Cool, what was the issue?

 

Turns out the mystery wire in the pics was the power wire for fans. It had turned black but when I started pulling it was actually orange. It wasn't powering the fans though so I started messing with it and the crappy splice job done at the + battery terminal was all corroded. replaced it with a pigtail from Oreilly's and voila! Power. Now just have to figure out why the drivers side fan won't turn off. Oh well, at least it won't overheat.

 

that's normally a stuck "on" relay

 

I replaced the relays as part of the troubleshooting but it's a possibility. I'm also dealing with a hypertech chip that may have changed the temp settings. I'm looking into DIY PROM gear to check that out.