Hi everyone,

So after adding a lower thermostat I had bad drivability problems because it turns out I never reprogrammed my Eprom, which the average person really can't do. So , I had to put the stock 195 back in and am running hot (or what GM calls normal 235 degree) again, which I hate doing.

I have heard that there are fan switches which will kick the fan on at 195 instead of 220. Do you all think this is a better solution, or will I have the same problems in regards to computer calibration/ having to reprogram the EPROM?

Is it better to just ground the wires and run the fans continously or will the car run too cold and never reach proper operating temp? Would a toggle switch throw off the computer as well?

Oh for a pre-computer controlled car....so many less problems......

THanks

 

I would wire it up to a relay, and let the fan temp switch do the work. (Wire up everything separately, so it works on it's own) That's what I did, even though my computer didn't control the fan. But since I went to a 2-fan set-up, I thought that was best.

 

I thaught that the fan switch was jus plug an play? Am I missing somthing here. I changed mine out on my 92 lo3 A couple years ago. Did i forget somthing?

 

Not if the computer controls the fan. You'll have to check to see when they started that. Read Willie's articles on fan set-ups and cooling.

 

First, there is nothing wrong with a 195 stat, that is where the ECM wants for all emission and driveability issues to be optimum. A 180 will work well and provide little variance in mileage since in stop and go traffic the average temp will still be in the 185-200 degree area. All thirdgens already have a relay if it's an electric fan contrary to the other post, the fan switch grounds one end of the relay coil energizing the relay contacts to close and provide power to the fan. Lot's of guys spend 40 or 50 bucks for a JET switch, NAPA stocks 2 different fan switches you can use in a TG, one at the stock 234 and a lower one that kicks on around 215 or so. They cost $19. With electronically managed engines, I have found that a stable temp is best usually around 185-220. Emissions work well, and mileage is generally good. 170 is too cold as you said, I tried it and lost 3mpg. I run a zz-4 block in mine with a 195 and a completly stock cooling system, never had a problem with overheating and it gets 25mpg in OD. The engineers try to keep the engine within a safe range temp wise as well as trying to reduce the number of times the fan cycles on and off. Constantly turning the fans off and on is hard on the charging system as well as the fan relay and fan motor. The fan switch doesn't care since the amount of current it switches for the relay coil is minimal. Hope this helps.

 

That's EXACTLY why all of the computer cr*p is gone! Now I can work on it without guessing, and without buying a laptop!