Fan Temperature Switch?

[90ZRJR1]

I could use some help guys! Is the electric fan controled by an external switch or is it controlled by the computer? I have a 1990, totally stock, and I would like to have kick on a little sooner. It seems like it kicks on around 240 degrees or so. What can I do? Thanks Jimfahne

[gbmidyear66]

Change the PROM in your ECU to have them come on earlier. Marc Haibeck offers a PROM upgrade that is a good choiuce

[Paul Workman]

As mentioned, Marc Haibeck's calibration upgrade for the 90 ZR-1 includes better heat control by way of operating the fans to both come on at 205* and turn off at 200*. I can tell ya it makes a world of difference - not just the fan operation, but the entire calibration package really improves overall drivability (IMO).

P.

[tomtom72]

Not to sound like a shill for one of our beloved ZR-1 Tuners.........but, I agree with Paul's statement 100%.

I've had my Z for 5 yrs and this year I finally broke down and bought one of Marc's reprogrammed PROMS. Man what a difference! On the face of it the price does seem steep. After all your car is not on a dyno and the program is not written for Your car while it is data recording on the dyno....but I can not describe how pleased I am with Marc's off the shelf PROM.

You can wire up a manual switch to turn on the secondary fan when the temps start to rise, or you can just turn on the A/C to get the secondary fan to help pull heat out. I did this for 4 yrs because I was too stupid and cheap to realize that Marc's program is a total package, not just fan call in temp changes.

My best advice is just call up Marc and mail order the PROM. The install is easy as it is a piggy-back that plugs into the existing PROM below the cylinder ident slots on the factory PROM. The only thing you need to do is remove the OEM cover from the OEM PROM and plug in Marc's PROM starting below the first 13 pin holes, slip it back into the ECM and push the PROM back into it's slot and you're done!

Sorry if I sound like a cheerleader, but this was the best $$ I spent on my Z in the five years of ownership!


Tom

[90ZRJR1]

Thanks for the info guys.Looks like I'll give Haibeck a call for an upgrade! Keep it revved up, Jim 1990 Blk/Grey #115

[Hammer]

I ahve Marc's prom also. Read up on what his prom will do for the operation of the car. Can't go wrong. The car will drive much better with his calibration.

Keep your old Prom in the static wrap your new comes in for later, selling the car or emissions.

Let us know what you think once you've swapped them and driven it.