Thread: Lower temp engine temp sensor needed.

OK here's the sitch:
Fans don't turn on until like 240F or whatever and I read that's by design, but in my opinion that temp is way too high, especially in a car that the AC doesn't work (different story: replaced condenser and compressor from junk yard and still has slow leak that I can't find, whatever.) So I have to jumper the fan relay whenever I drive more than 15 minutes, because it's summer. Then I have to pull the jumper every time I park because the fans kill the battery rapidly. It's a lot of hood opening and close to needing to replace the hood strut at this point. See the chain reaction?
So here's the question:
Is there an aftermarket temp sensor that will close the relay at a much lower temp? Or another known workaround.
Thanks.

Originally Posted by tomsteve

even if the AC isnt pumping cold air, wouldnt the fans kick on with the AC on?

Negative ghostrider. If the compressor doesn't activate due to low pressure switch not having enough reading, then the fans don't come on when you press the AC button, which essentially is useless if the AC doesn't have pressure.

Well I'm not going to redo the entire cooling system because I already do that and have been replacing the tstat and coolant every year so those aren't the problem. I replaced the temp sensor once as well but that was a couple years ago. So you're saying the OBD scanner will read a temp different than what the temp sensor tells it? If so then where does it get this alternate temp?
Thanks.

What does this mean? "a tune could turn the fans on sooner"
I was thinking about rigging a switch in the cab as mentioned but hoping I could just get them to turn on automatically when they're supposed to instead of letting it get to the point where the trans then gets up to 220 and the trans oil breaks down. again.
Thanks.

Other than the dumb factory gauge which I'd also like to replace with something accurate, I've blew 2 new heater hoses in 2 years before I started jumping the relay, and I also cooked a steak on top of the supercharger, in a pan of course, in less than 10 minutes.

Alright thanks for the info. I'll look into tuning the PCM, that sounds like a fun new endeavor. A sensor swap would be easier but I guess they don't make one.

Caspers Hi-Speed Fan Kits work great and are well made. I have installed several on Regals. You can install a relay in parallel with the manual switch and activate the relay with a thermal switch. Use the thermal switch to supply a ground to the relay and find an ignition on hot wire to provide a positive source to the relay. To tap in to the wires going to manual switch, fold the wire in half and burn the insulation off, twist the bare wire and solder to the correct wire going to the relay. Don't forget to put a piece of loose heat shrink on the wire before soldering. I install a Honda K swap hose adapter in the upper radiator hose and use a late 90's Honda Civic style thermal fan switch. Mounting the manual fan switch under hood makes for an easy way to test the fan motors periodically to make sure they are working ok and aren't too loud. This set up works well with a 180 stat, I don't think it would work with a 195. These Civic fan switches make at ~ 200F.