84 fan runs when key is turned to accessory

[brimis]

I just notice the fan runs without starting my 84. When I turn the key to the accessory position the fan turns on. The car is fine, no over heating issues, running temp is 197-200 city and highway. Any thoughts?

 

[slashnick]

Mine only runs the fan when it is above a certain temp. Try putting the key in when the engine is cold. It it comes on someone probably rewired it.

 

[Top]

Do you have any code 14 or 15, Coolant sensor? If the sensor is not reading the ECM automatically turns on the fan to run to avoid overheating. The second thing I would check is the fan relay on the drivers side wheel well. Make sure it is connected well. The relays are under $20.00 and yours is 20 years old now.



Good Luck

 

[brimis]

When the car is cold the fan will spin with just the key in the on position.

 

[JonM]

I just notice the fan runs without starting my 84. When I turn the key to the accessory position the fan turns on. The car is fine, no over heating issues, running temp is 197-200 city and highway. Any thoughts?

Try pulling the wire on the AC compressor (looking at the back of the compressor, at about 10 oclock) see if the fan shuts off.

 

[WhalePirot]

The '84 and early '85 are unique in that the fan is triggered by the relay mentioned from a SEPARATE temperature sensor, located in the pax side head AND by the A/C compressor. The sensor, under HOT (whatever temp.) conditions, grounds the relay, allowing the battery voltage to power the fan. This relay is located on the firewall, inside the engine compartment, about where your right toes would be, near the brake booster.

Lower temperature sensors are a bit harder to find, but are in various Corvette catalogs .

The ECM is not involved in fan control until later cars. The ECM on our gets coolant information from a different sensor.

 

[Jeff Henning]

brimis,

If your C-4 runs at 197-200 don't mess with it.
Most of them run 200-230 in heavy traffic. I have been trying to find a way to run cooler and have looked at changing thermostats, sensors, etc.

Jeff

 

[JonM]

 

[brimis]

Thanks to all, over the weekend I will do as mentioned and you posted.

 

[brimis]

I disconnected the plug on the A/C compressor that Jon mentioned is at the 10:00 position looking from the rear of the compressor and the fan runs. I then pulled the plug that is at the 2:00 position and the fan runs. The plug that connects to the front of the A/C has never been connected. I traced a single wire from the fan to the distributor cap. This may be why the fan runs when power is turned on. Yes?
PS I'll try to post a picture this evening.

 

[JonM]

Their is no wire that should be running to the distributor cap. I guess Bubba had the car before you. The above pic is exactly and only wires that should be running from the relay on the fender well under the master cylinder

 

[brimis]

Thank you, I will set the fan up the way it should be setup.
Might take a little time, but I'll get it.

 

[corvette66]

Funny Thing

With My 86, When I Turn The Car Off, The Fan Continues To Run. I Have To Turn The Car Back On Again And Off Again To Get It To Shut Off. (not Always) Weird Stuff