coolant fan switch

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Sep 3, 2006 | 06:21 PM

lawnjockey

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Cruising

Joined: Aug 2006

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coolant fan switch

I purchased a coolant sensor from corvette central to make my fan come on at 185 and back off at 170. when I installed it my gauge reads 299 and the fan never comes on. It is an 86 vette. what is up with this? any Ideas?

Sep 3, 2006 | 06:55 PM

CFI-EFI

Race Director

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From: The Top of Utah

It sounds as though you have installed your new auxiliary fan switch in place of your IP temp gauge sender. In an '86 the auxiliary fan switch is mounted in the left cylinder head. The gauge sending unit goes in the right head. If you don't have an aux fan, you have either wasted your money, or else you have some rewiring ahead of you. Your MAIN (or only) fan is controlled by the computer.

RACE ON!!!

Sep 3, 2006 | 07:42 PM

lawnjockey

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Cruising

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so this switch is only for the aux fan.I added on the aux fan, but i have no wiring harness or relay, what can i do to fix this so the coolant will remain low,
thanks

Sep 3, 2006 | 08:40 PM

CentralCoaster

Team Owner

Joined: May 2002

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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed

with CFI. You installed the fan switch into your guage sender location.

It belongs in the driver's side head. But fat chance installing it if your car didn't come with the aux fan. Your drivers side head will have a pipe plug in that hole that is near impossible to remove.

You could also hook it up to your main fan relay. Simply run the wire from your new switch directly to the green wire on your main fan relay, which is on the drivers side inner fender liner.

That fan switch is worthless anyways. I would send it back. Do you have the stock 195 thermostat? If so, it'll just make your fan run all the time, and can actually reduce airflow through the radiator on the highway.

Sep 3, 2006 | 08:50 PM

BADDUCK

Le Mans Master

Joined: Jun 2006

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From: One day you're a Comet...the next day you're dust... Arkansas

Quote:

Originally Posted by lawnjockey

That fan switch might be appropriate for a 160* thermostat. They make a on at 200 off at 185 sensor/switch that I use with a 180* thermostat. It is working fine on my Aux. fan. With that switch my main fan only comes one when I run the air.

Sep 3, 2006 | 10:05 PM

RRT vette

Le Mans Master

Joined: Feb 2006

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From: Louisiana

Quote:

Originally Posted by CFI-EFI

This is correct. If the switch has a **** looking connection it is the aux fan switch that goes in the drivers side cylinder head. The aux fan is infront of the radiator under the front bumper and is not used until engine temps reach 235*. If has a tooth slip on connection it is the temp sensor for the guage on the dash. Located in the passenger side cylinder head. The main fan is controlled by the computer and a lower temp would have to be burned into the chip.

Sep 4, 2006 | 11:21 AM

rick lambert

Le Mans Master

Joined: Oct 2003

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From: seattle WA

unless you're using a 160 thermostat that is the wrong temp switch.The aux. fan switch does go into the drivers head between #1 and #3, you'll need a fan relay for the aux. fan, usually located on the drivers side close to the radiator. The main fan is typically controlled by the ECM, HOWEVER, you can simply wire it a little differently..see tech tips, there's a write up on how to do it,without haveing to burn a chip or mess with the ECM. Both my main and aux. fans come on at 200 and off at 185. Of course I'm using a 180 thermostat.

To find tech tips, just click on "other" at the top.

Last edited by rick lambert; Sep 4, 2006 at 11:25 AM.

Sep 4, 2006 | 11:33 AM

lawnjockey

Thread Starter

Cruising

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thanks for all of the help, I do have a 160 thermostat and there is a temp sensor in the passenger side head, but I have never connected anything to it. I got the car wrecked 10 years ago and replaced the whole radiator area which came with a b4p fan. Now this is what is strange- the wrecked radiator had a fan in it, but no relay or harness.
I took the cfs back out and put the old switch back in. I now have it in the pass head, do i splice it into the green/white wire comming out of the relay?