Cooling Fan Switch
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Intermediate
Joined: Jan 2006
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Cooling Fan Switch
Now That Its Getting Warmer In Cincinnati,oh. My 91 C4 L98 Vette Is Running Alot Hotter, I Bought A Fan Switch That Turns Both Fans On At The Same Time But The Instructions Are Crazy. Has Anybody Ever Used One Of These And If So Can You Tell Me Whitch Wire I Have To Jump To Make It Work? Each Of My Fans Have Three Wires ,im Not Sure Whitch One Im Suppose To Jump. Thanks In Advance Garvette 91
Le Mans Master
Joined: Jun 2006
Posts: 5,642
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From: One day you're a Comet...the next day you're dust... Arkansas
I'm not sure how to wire it, but why don't you try just connecting it to the aux. fan only and see if that solves your problem. If it kicks in at say 185 degrees instead of say 228 degrees that will probably solve the problem.
Last edited by BADDUCK; Jun 16, 2006 at 05:11 PM.
Le Mans Master
Joined: Dec 2000
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From: San Diego, Ca
Your fans are driven by the ECM based on inputs from the Coolant Temp Sensor or the a/c pressure switch. Since all the ECM does is supply a ground for the fan relays, you need to tie you new switch into the ECM side of one or both of the Relays. The switch will thread into the boss in the left head between the 1 and 3 cylinder - have some extra coolant on hand as when you remove the plug, all of the coolant in the head is going to drain out. Use a little sealant on the switch and thread it into the head. Splice the relays into whatever wire came with the switch and the fan or fans will now come on at whatever temp the switch closes at. Do not remove ECM control from the circuit - you will still want both fans to come on with the a/c and that's at a much lower temp than any threshold for these switches.
Team Owner
Joined: May 2002
Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
This is for an 85, but if you can understand a wiring diagram, it will be easy to do on your year.
This is everything you need to know. I don't know what their switch kit comes with, I used a $1.99 switch from radioshack and 6' of wiring.
http://webpages.charter.net/khasting...noverride.html
This is everything you need to know. I don't know what their switch kit comes with, I used a $1.99 switch from radioshack and 6' of wiring.
http://webpages.charter.net/khasting...noverride.html
Thread Starter
Intermediate
Joined: Jan 2006
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My Connector Has Two Wires Coming Off It. It Says To Wire 1 Into Each Fan Switch. I Just Dont Know What Wire To Conect Them To. Iech Harness Has 4 Wires Comming Out Of Them. So Im Not Sure Which One To Splice Into.
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
The hardest part will be to remove the pipe plug in the head to install the Fan Temperature Switch.
There are two Fan Relays. One for each motor.
Each relay has four wires going to to it.
You plug one end of the new fan harness to the Fan Temperature Switch. Plug end looks like a mushroom. Then you crimp one wire from the harness on to the DARK BLUE wire at each of the fan relays.
From the PDF file on Mid America's site it looks like they use solderless crimp connectors. The connector pierces the insulation and makes contact with the center conductor.
To test the fans once you've done the wiring, remove the connector at the Fan Temperature Switch and ground it. You can stick a small nail or jumper wire into the plug and then ground it. Turn the ignition on, and both fans should run.
There are two Fan Relays. One for each motor.
Each relay has four wires going to to it.
You plug one end of the new fan harness to the Fan Temperature Switch. Plug end looks like a mushroom. Then you crimp one wire from the harness on to the DARK BLUE wire at each of the fan relays.
From the PDF file on Mid America's site it looks like they use solderless crimp connectors. The connector pierces the insulation and makes contact with the center conductor.
To test the fans once you've done the wiring, remove the connector at the Fan Temperature Switch and ground it. You can stick a small nail or jumper wire into the plug and then ground it. Turn the ignition on, and both fans should run.
