cooling fan problem

[Svosaver]

I have an 84 SVO and the cooling fan runs all the time. Key on ice cold still runs. HELP!

[Corrugated]

Check the fan controller / relay under the dash near the steering column, as well as the wiring and connector going into the controller for signs of overheating, etc. I believe there is also a fan switch at the engine as well (could be faulty / stop open or closed).

[Svosaver]

Update, I put another module in and disconnected the sensor and the fan is still on! Does this go through the ECU. Any ideas?? Thanks

[KevinK]

The fan operates by two separate signals. One is by temp switch at the engine and the second Is by an override from the ac circuit. Whenever the ac compressor is turned on, the fan is forced on. This also includes the defrost function hot or cold. Defrost is designed to use the ac to provide dryer air for a more effective defrost.

With the fan on at all times, it would indicate a failure of both circuits. I believe they meet at the fan controller relay which is in a small black box above the pedals. Normally, is has "TRW"on it. Removing the relay should disable the fan. Otherwise someone has rewired something.

[Svosaver]

I know they meet at the relay, I replaced it but still on. New problem last night,I left the battery cable connected and the battery was dead this morning. I checked and nothing was on in the car, no lights no switches at all. Is there a way to see which system is draining the battery. I'm woundering which would be most likely to drain the battery with the key off. Car is starting to annoy me! LOL Thanks for any help given!

[Svosaver]

Solved the fan issue! To much paint under the ground. Still working the dead battery, I found that the alternator is hot when the key is off. Any ideas? Thanks for the help!

[KevinK]

Not an expert, but I have heard numerous times the a bad diode in the alternator will drain the battery. There may be some troubleshooting in the Ford manual. Just. Unplug the alternator and test overnight .

[Meotchh]

Not real sure how too much paint under a ground would cause the fan to run all the time. A poor ground connection should prevent the completion of the circuit & prevent the fan or connected device from turning on.
Since you have an 84, you could have many issues. The harness in the 84 is known to deteriorate & cause problems throughout. If you do not have a digital multi-meter (DMM), you can start by disconnecting the alternator & see if your battery still dies. Ultimately you really should use a DMM to assist in troubleshooting any current drain issues. That will allow you to see exactly how much drain you are dealing with. You should also start with a good battery that is fully charged.
Do you have any aftermarket additions to the car's electrical system?
Has the harness been modified in any way?
Has anyone performed electrical work & spliced any wires or bypassed any stock connectors?
Is the charge lead from the alternator to the battery melted at the plug in the middle or is the plug cracked?