Log in

View Full Version : fan switch


maroman88
06-15-2005, 02:01 PM
is there a way to install a manual fan switch on my 92 RS 305 tbi?
it runs real warm n i would like to make it cooler.
what wires could i tap into etc...?

deadtrend1
06-15-2005, 07:21 PM
I bought a 30 amp 12v relay and a simple toggle switch from radio shack. Theres a diagram on the package for what wires go to what plug on it. Theres 4 wires to connect to it all together. I mounted it on the passenger side next to the radator, behind the headlight.

I know theres probably a better way to do it, but this was years ago with my limited knowledge. This way allowed the car to use the factory fan switch also. I used a relay to minimze the current running through the switch when the fan is running.

First, I tapped a wire onto the + side of the plug for the fan. Easy way to do that is to use a test light, turn the a/c on and see what one makes light go bright. That wire goes to the 12v out of the relay.

Next, Ran a fused wire from my positive lead of the battery, to the 12v in of the relay.

three, ground the relay. Fair enough explanation.

step three and a half: Run a wire from the low voltage input of the relay. to a switch inside the car. I also down the road put in a little LED lamp inline with the switch for ****s and giggles.

five: Ground the switch, LED, and wired the switch to a 12v ign source so the fan doesnt run when the ignition off.

nj85z28
06-17-2005, 12:49 AM
Why dont you just buy a low temperature fan switch to replace the original one?

Slow Z
06-17-2005, 02:04 AM
Its been a very long time since I've done this but I believe there should be a temp sensor on the driver's side cylinder head. If you cut and ground the wire going to it the fan will stay on.

HardcoreZ28
06-17-2005, 07:42 AM
Why bother with a low temp switch? If you don't want to wire in a manual switch just have someone burn a new chip for you with lower fan on temps. Save yourself the headache of having coolant everywhere.

maroman88
06-17-2005, 09:54 AM
ok well i got a better answer on TGO. i tapped into the green/white wire on the fan relay, ran a wire to a switch and a ground from the switch and now it operates manualy or automaticly...no mess, took about 5 minutes and it stays at around 180 at all times. thanks guys

deadtrend1
06-17-2005, 05:03 PM
ok well i got a better answer on TGO. i tapped into the green/white wire on the fan relay, ran a wire to a switch and a ground from the switch and now it operates manualy or automaticly...no mess, took about 5 minutes and it stays at around 180 at all times. thanks guys

i knew there was a easier way, just at the time i did that years back I wasnt a member of TGO, nor smart enough to know where the fan relay was.

maroman88
06-18-2005, 01:07 AM
i had no idea either but they had a picture so i printed it out and matched up the wires lol

camaro2you
06-18-2005, 08:50 AM
you still got that pic?

maroman88
06-18-2005, 09:00 AM
http://thirdgen.org/techbb2/attachment.php?s=&postid=2313587

should be on the driverside firewall

and heres a different thread
http://thirdgen.org/techbb2/showthread.php?s=ae297ad416b3cd606e0fee32bd5644ff&threadid=293680&highlight=manual+fan+switch

bokey
06-19-2005, 10:39 AM
ok well i got a better answer on TGO. i tapped into the green/white wire on the fan relay, ran a wire to a switch and a ground from the switch and now it operates manualy or automaticly...no mess, took about 5 minutes and it stays at around 180 at all times. thanks guys

I did this last night, but my car started to act funny once everything was hooked up to the switch. What would happen is, I would turn my car on, the RPMs would drop to 1000 then rev all the way up to 3000 for about 3 seconds then it would gradually fall to about 1500 RPMs. For the ground, I used a connection to the chassis, and for the other end, a connection to the green a white wire. All of this was hooked up to a single pole double (3/4 HP rating)... Any ideas?

maroman88
06-19-2005, 12:02 PM
there might be 2 green/whites, one on the AC relay and one on the reg fan relay try the other one. the 2 relays should be next to each other on the fire wall

bokey
06-19-2005, 01:41 PM
there might be 2 green/whites, one on the AC relay and one on the reg fan relay try the other one. the 2 relays should be next to each other on the fire wall

I do, the switch works, its just the car acts weird... :?

camaro2you
06-19-2005, 06:23 PM
unhook the switches and run the car and see if it does it.

bokey
06-20-2005, 09:18 AM
unhook the switches and run the car and see if it does it.

I did, and it still did it. After I let the car sit over night, it was fine. I was at the womans house and hooked it up there, and didn't have any more issues. Weird...

Now I just got another problem, now a loud rattling sound is coming somewhere from my axel back and i think my pulley tensioner is starting to go. One thing after another lol...