I have a 1985 Z28 Camaro with a TPI. My fan quit working recently so I started replacing stuff. I replaced the fan relay and fan motor. Then I went to replace the fan switch and just saw a plug where the switch normally is. If there is no switch, then what controls when the fan comes on and off?

 

Hi,

Not sure on the earlier 3rds but if you have the dual
fans ECM controls the primary fan and the head switch
controls the secondary.

Later

jaykar

 

My car is a single fan setup. I did figure out why the fan isn't coming on. The plug that goes into the fan relay is shorting out. If I hold it in the relay, the fan works as it should, but if I let go, the fan quits working.

New question. Is there any advantage to using the fan switch in the head or is the computer controlled method just as good? If I were to use the switch in the head, how do I go about wiring it so that the computer doesn't try to control the fan as well?

Thanks

 

Hi,

Since your running a single fan setup you will have to
change the setting on, fan on, fan off temp control with
chip work.

I suppose if you wanted to change over to dual fans
like the later cars you could always run a secondary
temp switch of your choosing(Temp Wise) and set the primary fan with the chip.

All that turns on the secondary fan on is hot to ground
at a certain value.
HTH

Later
jaykar

 

My 1985 Z-28 (single electric fan) also had a plug in the head where the fan switch would have gone. The fan worked normally the entire 4 yrs i had the car. My brothers 1985 Z also has the same setup. Neither my car nor his had the wiring which would have connected to the fan switch so I assume the ECM is controlling the fan on 1985 TPI camaros (using the temp sensor in the front of the intake under the throttle body) No wiring diagram I've seen shows this though.

BTW i live in NW iowa and sold my 85 Z in 2000, any chance its the same car?

 

From what I've read, the 85 TPI cars use the temp sensor in the front of the intake manifold to monitor temp and the ecu commands the fan on and off. My 89 T/A had the switch between the 6 and 8 cylinders.
Today I was driving around and my car started overheating again. I checked the relay and found that the relay isn't getting a command to turn the fan on. I've replaced the fan relay, coolant temp sensor, gauge sensor, and fan motor. I also recently replaced the pcm with one from a 85 T/A TPI because my original pcm wasn't commanding the torque converter.
I'm originally from Inwood, IA. I bought my car in Feb of 2000 from a guy from Inwood also. I don't remember the last name but his first name was Bruce.

 

hmm, i know that guy. PM sent