Rad. fan run-key off

[spfld03]

Has anybody run into a 1999 escort that has a problem with the coolant fan running when the key is off. It will eventually run the battery dead. I checked engine coolant temp sensor and it isn't showing a false reading. I also checked connector in front of console for meltdown, but only found a few terminals that were corroded.Thanks ahead of time for any replys.

[Davescort97]

Originally Posted by spfld03

Has anybody run into a 1999 escort that has a problem with the coolant fan running when the key is off. It will eventually run the battery dead. I checked engine coolant temp sensor and it isn't showing a false reading. I also checked connector in front of console for meltdown, but only found a few terminals that were corroded.Thanks ahead of time for any replys.

The engine coolant temp sensor sends a signal to the PCM (powertrain control module) which in turn signals the CCRM (constant control relay module) to turn on the fans. Either the PCM or CCRM is at fault when the fan runs continiously. There is a 40 amp fuse in the engine compartment.

[AzTumbleweed]

I don't have a schematic but I would suspect a stuck relay.

[spfld03]

Thanks for the reply, I was wondering where the fan relay and ccrm were. My scan tool had a 'quick' fix topic on this problem. It said that o2 sensor #1 would short internally and cause connector 220(Ithink) in front of floor console to melt and cut on fan. I initially unplugged o2 sensor and the fan cut off, I thought I had found problem. After checking connector 220 I only found that a couple of terminals were corroded. After recconecting I found the fan would run all the time, regardless of key position. I think I need to find a wiring diagram.

[rhandwor]

http://www.alldata.com/ have good diagrams. Cost $25.00 per year.
Normally a fan will run until the car is cool. How long are you talking about.
Put a charger on the battery and time it, it should shut off within 20 minutes.

[mightymoose_22]

It sounds like you have already found your problem. Get your hands on a wiring diagram and it should become clear.
If unplugging the O2 stopped the fan then you are half way there... just trace the circuit.