My electric fan runs all the time. When you switch the Key to the on position it doesn't run but as soon as the engine is running the fan turns on and never turns off until I shut it down. I would figure that this thing wouldn't want the fan running constantly. It barely gets above 120 degrees or so. Also I've swapped this TPI into my Carb car. I don't have the Fan switch plug hooked up to the AC yet so I don't know if thats making a difference or not. I haven't gotten to put any real miles on it yet either. It hasn't kicked any codes other than the 12 code and thats normal so I don't really know whats going on.

Any ideas would be appreciated.

Thanks

 

So I take it everyones fans run all the time?

 

The fan should only run if the temp is reached ~225F and both fans will run if engine gets to ~238F

The passengerside fan will start when AC is on, and then ~10secs later the driversidefan will start. (when AC pressure switch got the right pressure)

So NO the fan/fans should not run when starting the engine (if none of those things I just wrote about is filled)

Do you have a custom PROM in it ? or did you change some wires recently ?
Maybe you got an bad sensor. I would have it checked..

 

See I converted my Car from Carburated to TPI. This is the only problem that I've come acrossed at this time. I haven't checked the sensor but I figured that that might be the problem. I've got 3 other intakes with sensor in them so I guess I'll pull one out and see if the fan comes on when plugged into it. My TPI setup is out of an 86. I only have one radiator fan. Do you think that using a sensor out from the other intake and just plugging it in will show me if mine is malfunctioning?

 

You can measure the ohms in the sensor and see how that turns out. heat it up and measure and see how the ohm changes. Not sure how the fan are controlled in 86 but in 89 its controlled thru the ECM and the sensors..

Try another sensor and see if theres any changes, also check so the AC pressure switch isnt grounded or unplugged, then the fan will start because theres no switch in place.

 

Thanks for stickin with me on this issue. Turns out it will be a simple fix. I don't have the presure switch for the AC yet so that plug has been hanging. Since that switch was open the ECU was thinking that the AC had presure building so it was running the fan. I jumped the terminals and the next time I started the engine the fan didn't come on. I let it warm up and as you said around 225 or so the fan kicked on. This also solved my idleing issue. The Swap is just about complete now. I just have to do a total fluid change and I'll be just about ready for the road. BTW you car is awsome!!

Thanks
Again.