i have the usual probe-in-radiator fan switch. do any of you guys know how to wire a pot in the circuit to make it adjustable? How many ohms would i need for this Pot! the fan is on at 180 and it runs all the time! i need to cut the sucker down or run my battery down! thanks

 

Get a correct factory switch for the fan that is installed in the engine block, or if you don't want to run at such a high temp get a 180 degree switch instead of the stock 195 degree switch. A correct fan switch should come on at the normal set point of the switch and shut off 20-30 degrees below so that the fan cycles on and off. On my T/A tha fan comes on at 195 degrees, but the temp will continue to rise to about 220 degrees, then the temp drops to @ 180 degrees and the fan suts off. Also the fan is on switched on power, it won't run unless the key is turned on.

 

I have a similar set up on my V8 (LO3), I have probe-in switch installed next to my radiator that has adjustable dial so can adjust the temp in which the fan kicks on at. I live in the Dallas/ Ft. Worth area so I wanted my engine to run a little cooler than 220 while I fight traffic. However, I need to find a way to wire it to something that only has power while the key is on. Now, it's wired to the battery and runs while the car is shut off. If anybody knows a convenient place to tap into or or advise on a better set up I would appreciate it.

 

Your fan motor draws quite a bit of current. You should run the motor off of a relay. I would install a Bosche type relay on the fender well nearest the battery and run a #10 ga wire from the battery to the common side of the relay with a 25 or 30 amp fuse inline. Run a second #10 ga wire to the fan motor. Do you have a fuse box under the hood? If so, you can catch a switched on power source at the fuse box. If not, you could use a positive terminal on your ignition system, just make sure that it is a 12 volt source and not after a ballast resistor that will drop voltage down to 6-8 volts. Just take power from your switched on source and run to the relay coil. Run another wire to a chassis ground off of the other side of the coil. The only other thing you need is a ground for the fan motor to complete the circuit. Depending on the rating of the thermostat control, you could hook it up inline with either the motor or the relay. either way it will turn on the fan when the temp gets too high and shut off when the temp drops.

 

question on running the fans off the ignition switch....they run and work fine until you want to turn the motor off.....at which point my galloping 350 hesitates to shut down..could it be the resistance the fan makes from spinning keeping fire on the coil? How can i fix this aggravation

 

Wdig, both Derale and Hayden make adjustable fan relays so you can have your fans come on when you want them on and you can also keep your factory system in place. They are easy to install and both work well. You can also install manual fan switches. I have one for each fan along with an LED wired to each relay so I know when the fan/fans are on. Click on "User CP" at the top of this page and then click on "Cooling" and you should see some fan mods by Willie that work very well.