firebirdjosh

iTrader: (1)

So I smell burning yesterday then my car overheats. The fan doesn't turn on for diagnostics, and last time I checked a few weeks ago it did so I figure thats a good place to start checking. This is the weird part. The relay works. The fan works (tested direct to battery). However the Brown wire that is switched to the fan when the relay is activated is 12V but it can't power the fan. It can't supply enough amps to move the fan. I basically need to know where the wire runs to so I can fix this. I don't understand how it can be 12V and not supply enough amps since it draws what it needs from the battery. No fuses are blown in the fuse panel either, and I don't see any burnt wires.


*I ran a wire from brown wire to ground and didn't see any sparks. Any idea where the brownish/orange wire runs to from that relay?

john1221

Josh, you never said how you tested the relay but one word of advice-don't short things to check for sparks! Pull the relay out of the socket and check the condition of the socket. Mine was melting. Under no load a poor connection is still a connection and voltmeter will read 12v. When the relay comes on to energize the fan the voltage drops across the poor connection and even go to 0. Basically in a poor connecting wire or connector only part of the total surface of the connetor is making the connection. more current flows through this smaller surface area than it can handle. This makes the poor connection really hot. The expanding hot metal breaks what was left of the connection and you get 0v. This happens really fast you might see 12v on the fan for a split second but I doubt your meter is fast enough.

Replace the relay socket and relay. The aftermarket ones are far cheaper than the dealer but I prefer to keep things stock for the next guy who has to figure it out. and don't buy used parts!
What is the resistance of the fan motor? Mine is 7.5 ohms. Maybe mine is too low..