Fans Turn on Even Though Car Not Running

[Ron]

Can anyone who is 110% certain tell me if the Joe Cool requires any wiring or other alterations, or is it simply pull two relays and plug it in?

[dmc6960]

I can. Because while at DCS someone I was with wanted to buy one, but Dave Swingle cautioned first to make sure the wiring for the fan circuit had NOT been modified. I checked his car and indeed it had. On this particular car it was not a bad modification, but it would have caused the Joe Cool to not work.

[82DMC12]

I just put a Joe Cool in my car. Basically if your fans work correctly with the three plug jumper, take the jumper out, plug Joe Cool in, and it should work correctly. Any other "mods" and all bets are off!

[DMCMW Dave]

Yes, for the fan controller to work (not just this one, but even the old FanZilla or the other plug-in units) the wiring in the car must be factory stock.

The most common mod is that some people have eliminated the fan fail socket wiring and just connected the fan wiring together underneath (with or without fuses). If this has happend the Fan Controller will not function. The fans will not work with the Controller but will work if you put the relay back in the second socket.

The "tell" on this is if your car has nothing plugged in to the far left/blue socket, the modification has been done. If there is a blue fan fail module there, I'd suggest you unplug it and see if the fans still work. If they do, someone did the mod and left the fan fail module in place for appearance.

[lazabby]

Just so that everyone is clear on it, Joe cool replaces the two relays that go into relay sockets #6 and #7. As I understand it, #6 controls the cooling fans and#7 controls the fan fail.

[DMCMW Dave]

Just so that everyone is clear on it, Joe cool replaces the two relays that go into relay sockets #6 and #7. As I understand it, #6 controls the cooling fans and#7 controls the fan fail.

Not exactly. It changes the way it works completely.


In the original setup the relay in Socket 6 is powered from the battery and triggered by the otterstat or A/C. The relay feeds the breaker, which feeds the blue module. The blue module feeds (the outer pins) the two fans and has a circuit to turn on the light if either fan goes open.


In the Sequential Controller, the control box is powered from Socket #6 and is still triggered by the otterstat and A/C. The circuit in the box powers the fans directly through socket #7, and also can light the "fan fail" light which is the center pin of socket #7. Inside the box are two relays, as separate one for each fan, as well as the time delay circuits. The circuit breaker is bypassed.