Stock Fan Switch Always Grounded? - Third Generation F-Body Message Boards

87GTAj · 05-08-2009, 06:46 PM

Here's the story:

When I bought the car, the previous owner had wired the fans to come on with the ign. I didn't like this so I picked up a fan switch relay kit - it's designed so the relay gets 12V when a temperature switch hits the switch temp and turn the fans on. Regardless of where I put the switch, I could not get the fans to kick on. I decided I'll tap into the factory fan switch between #6 and #8 cylinders and instead use that to ground the relay versus giving it 12V. The connector had been fried by the headers when I got it, so a new connector went on. I also ran an extra ground wire on a switch to the relay so I can have manual control if I want it. Well I put the key to ign to test the manual switch, and the fans kicked on right away. The manual switch was off and the car hadn't been run for a couple of days and is in the garage. Is this a sign of a bad sensor?

//<86TA>\\ · 05-09-2009, 05:17 PM

the stock relay connection is not grounded when the engine is cold. After it warms up, it grounds out and turns the fan relay on.

If the pin in the center of the stock fan switch has continuity to ground at all times, its bad.

87GTAj · 05-09-2009, 05:48 PM

Well the factory relay setup has been completely bypassed - aftermarket relay controls the fans. I just seem to have continuous ground at the factory fan switch. I figured that meant it was bad, just wanted to make sure. Probably going to buy a Hypertech 200/185 now. Thanks.