cooling fan switch

[betterman]

I noticed the other day that my cooling fan stopped working. Isn't it supposed to run all the time if defrost or a/c is on? It just stopped working a little while ago and i was wondering if the codes would tell me if the switch is gone or if the fan is gone? It has no problem with the temp rising to high when its on the highway but when just sitting in traffic the temp gets higher than it normally sits. I'm not to worried about overheating because its -25C and i don't drive around that much.

1992 mtx
stock

 

[projectSHO89]

I just posted a long winded expose on how to diagnose the cooling fan circuit not more than 3 days ago.

Go here: http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=005071

Then ask.

Steve

 

[betterman]

After reading that you will have to give me a bit of a vocabulary lesson. First of all where is the ircm located, where is it connected to and what does it look like? Same for the ect sensor. Also what is vbat? Sorry for all the questions but I have very little knowledge when it comes to the internal workings of electronics. You also mentioned in the post that cleaning of some connections might help. What connections should i clean?

 

[projectSHO89]

IRCM = Integrated Relay Control Module. Later called the CCRM (Constant Control Relay Module). It is the black box with the large letter on its label. Remove the plastic shroud on the top of the radiator support (the one with the emissions labels on it).

ECT = See SHOTimer's post in the above mentioned thread.

Vbat = Shorthand for Voltage(battery).

As for the connections, the ones in question that are likely suspects in this circumstance are the conectors for the ECT, the IRCM, and the EEC-IV computer (large connector on the engine side of the firewall). Disconnect the battery before plugging and unplugging and connectors.

Hope this helps.

My target audience was intended for someone with some electrical or mechanical skills. Happy to help you develop any you need.

Steve

 

[BeatDaSHO]

just to let everyone know.......if there is no freon in the A/C compressor, then the fan will NOT kick on even when switched to defrost.

Greg

 

[SolidState]

yes it might. Mine does. I have no freon in my car.

 

[projectSHO89]

It depends on the year.

Most 1st and 2nd gen SHOs have the pressure cycling switch in the power circuit for the compressor clutch. There is no feedback to the PCM to tell it whether or not the AC system is charged.

 

[rangerj]

Steve,

I got the book you recommended, Ford Fuel Injection & Electronic Engine Control, by Charles O. Probst. It is outstanding. This is exactly what I have been looking for.

At $22 bucks (Amazon) it is a heck of a deal. Anyone serious about working on their SHO should have this book. Thanks again Steve. rangerj

 

[betterman]

The codes blink out on the check engine light right? Just checking because that site with the codes and procedure doesn't mention anything about it.

 

[projectSHO89]

Betterman,

Yes. Plug in the jumper with the ignition off.

Sit down behind the wheel, pick up your pen and paper, then turn the ignition to RUN. Start watching the CEL. You can repeat the test as many times as you want or need to by turning the ignition OFF, then back on.

To reset the codes, remove the jumper wire at any time while the codes are flashing the CEL.


rangerj,

Hehe, it's chock full o' Ford goodness.. Good for any Ford fuel injected engine!

Steve