why is my electric fan on when i start the car cold and the ac is not on. the temp of the car can be at like 100* right after start up in the mourning and ac off but the electric fan is on. what is wrong here?

 

You could have one of a few things.

A sticking relay,

A wire grounding out somewhere that leasds to the relay,

The ECM temp sensor is bad or,

The pressure switch got accidentally knocked off your A/C line (small round plug w/a blue & a black wire on it)

 

thanks very much, how would i go about checking those and which should i check first?

 

If you have some extra wire laying around (like speaker wire or whatever) you could jump power to the relay from the battery.

The green/white stripe wire is negative & the tan/white stripe is positive from the fuse box

Jump the positive wire 1st (car/ignition off). If your fan kicks on then, the green/white wire is grounding somewhere.

If it doesn't come one, leave the positive wire on. Ground the relay to the engine or any close bare metal part breifly & repeat a few times, listen for the relay to 'click' (both when grounded & ungrounded). If you're not hearing that, you've got a stuck relay.

Bad temp sensors usually will throw a code but, nothing is perfect. It's an inexpensive item to replace though if you feel it might be the culprit.

The A/C pressure switch.. well.. I'm sure you know how to see if something's plugged in or not

Highly unlikely (since it never does anything) but, the fan switch in the pass side head could be faulty as well. That you can test by simply unplugging it & start the car. If the fan stops, it's bad, if it keeps running, that wasn't it.

 

ok i just looked in there closely and saw that the green wire with a white stripe is just laying on the front crossmember unplugged. where is this thing supposed to go?

 

"laying on the front crossmember unplugged", do you mean unplugged from the relay ?

 

ok i looked again around by the front crossmember there are two wires unplugeed. a solid green wire and a solid blue wire. the blue wire's connector has been burned by the exhaust. these wires are far from the fan relay on the firewall
thanks deadbird

 

After opening my eyes, I realized you have a TBI. Unfortunatly, I don't have a diagram for a fan setup for that & from the looks of it (by the one lousy TBI diag I have), the ECM has nothing to do with it's operation.

Looking at a carb'd elec fan diagram though, the relay ground is a solid green color which may/may not be the same for your car.

I'm fairly sure the other wires were the same for pretty much all as far as power goes. The relay should have a thick red or orange wire comming from the battery to the relay. A similar sized wire that is black/red stripe should be going to the fan & the tan/white stripe is +12v to the relay. You may want to trace the remaining wire to see where it leads.

If the relay is grounded, since the tan wire is switched by ignition, the relay will energize & make the fan come on as soon as you turn the key to the 'run' position (and constantly run after the car is running).

Did this just start happening or was the car like that when you got it ?

 

it has always done this, thanks for the help i will trace those wires tommorrow (actually later today)
thanks
brady