IF I INSTALL A MANUAL FAN SWITCH, AS SOLD BY MIDAMERICA, ET AL, WILL THE TEMPERATURE TURN ON/OFF FEATURES STILL WORK OR WILL I HAVE TO TURN IT ON AND OFF MANUALLY EACH TIME? HOW DOES THE FACTORY SYSTEM INTERACT WITH THE MANUAL?

I'D LIKE TO BE ABLE TO TURN THE FAN ON AT WILL BUT DON'T WISH TO LOOSE THE AUTOMATIC FEATURE.

I've got the same kit

Works normally

Just watch using that switch

You can quickly kill the battery, which will do in the alternate

Been there, broke that.

Yeah, the fan relay has constant 12V to it.

I don't know why GM did that, the fan is totally useless if the engine and water pump aren't spinning.

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OK, NOW I GET IT, I WAS A LITTLE PUZZLED ABOUT THE BATTERY BIT :-P DUHH--

Don't buy the kit, it's overpriced and nothing more than a switch and some wire.

An inexpensive toggle switch from any parts store is all you need.

The fan relay is always powered and is turned on by grounding the relay (done by the CCM). The ground circuit is a very low amp circuit so any switch will work.

Just connect a wire to the ground wire on the relay, run it into the cab, hook it to one pole of the switch and a wire to a ground from the other switch pole. Very easy to do.

Using the switch will do nothing to battery - nothing. Power to the relay is shut off when you turn the key off.

The only thing that can happen (at least on a 92-93) is that using the switch will throw a code in Quad Driver #4.

Quad Driver 4 monitors voltage in that fan circuit and getting the code means nothing. It won't throw the "check engine light".

I've had that switch installed for 7 years, works fine, though I don't use it very often.

I'd have to look under the hood for the correct wire color to splice into but can do that if you want.

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My fans stay on with the switch ON and the keys OUT

"Using the switch will do nothing to battery - nothing. Power to the relay is shut off when you turn the key off."

No. As you said earlier, the relay is always powered. If the car is off and I turn the fan override switch on, it will ground the relay and run the fan and drain the battery.

It's loud enough that you should hear it though unless you're at a rock concert or a race track.

I honestly don't know what their kit is. I used a double pole switch on mine, and it grounds out both fan relays to force them on. And when the switch is off, they operate like stock, and independent from each other. Probably cost $8 at radioshack plus some wire.

Here you go, good thing I saved this. It shows a DPDT switch, but DPST works as well. If you only have or want one fan on, then a standard SPST switch is all you need.

You gotta put your car year in your sig or posts. There a ton of little differences between years.


http://webpages.charter.net/khasting/techinfo/fanoverride.html

THIS WOULD BE ON A STOCK '87.

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GM musta designed the 92-93 better then. No power to the relay(s) with the key off.