Hey guys, I am completely stumped, maybe I can stump you too. Hopefully not. heres the history: 1992 camaro rs, has the electric fan. When we bought it the fan would turn on sometimes and sometimes not. Then one day it just quit working unless you have the a/c on. So thats not a big issue, I know what that problem is but I have the a/c on anyways. Then even with the a/c on that one quit working. Replaced the fan motor and it worked perfectly. Until a few days ago it was going bad. Sometimes it would come on, other times I would have to 'jumpstart' the fan by turning it and then it would start. Couldnt believe the motor was already bad seeing as it was only a couple months old. I had spare working relays around so I tried several and nothing got it to work, checked the fuses which were all good, tested the voltage at the plug which read 12.53, tried cleaning the plug and making sure the pins were straight and going in the correct hole and everything was normal. So I figured it HAS to be the fan. So I bought a new one, and of course it doesn't work. Hot wired the fan to the car battery, worked perfectly. Still have voltage coming to the wires, nothing persists to happen. I got so mad I cut the plug off, attached some female blade connectors to the wires and hooked them up to the blades on the motor, making very sure not to get them close to each other. Nothing. Any ideas?

 

Did you check your ground? Have you checked the fan switch?

 

Considering you are reading the proper voltage at the plug when there is no load, and that a good fan does not work when connected, is an indication of high resistance in the fan power circuit. Make sure all connectors are clean & tight, check wiring for partial breaks, verify the fan relay is in good condition (relay contacts corrode over time and produce high resistance, so you may want to try a known good one). The power to the relay contact is through a fusible link, so check it in case it may be partially burned out or making poor contact.