Possible Cooling Fan Issue

[JRA2000TL]

I've been having problems with my 95 running unusually hot. I found the upper radiator hose leaking, so I replaced it. I found out AZ sells the wrong upper hose. I compared mine to others' at the SESHO meet. In any event, I "made it work" with the hose they gave me. We pressure tested the cooling system, and it held; no leaks.

Now, I'm thinking, I haven't noticed the fan come on. The car still goes above N but not quite to the H, although dangerously close. I go to do the EEC test to see if the fans will kick on, but the gray singe pin female connector is MISSING! In the pic below, I have the EEC plug and the ABS plug held up. The small gray plug that branches off cannot be found. I swear up and down that I've pulled codes on this car and it had it, but there's no evidence of it "breaking off". I've looked everywhere. There is a blank plug that's plugged in a connector coming off the harness that powers the CID, but that's not the right plug. The plug on the right is slightly melted; that's why it looks gray on the bottom--that's not the single pin plug.



How can I test for codes now if I need to?

Also, if it's the CCRM, does an 89 one work? I have a spare that I pulled from the j/y. How else can I test the fan?

 

[NotSoSlowSHO]

You can test the fan just by disconnecting the harness and jumping it straight to the battery.

The fan doesnt care which side is + or -

If the fan kicks on, well, it probably isnt the fan.


I have seen a fair share of dead fans though. They are brushed fans (use brushes) and the brushes wear out. Ive rebuilt fans before using off the shelf brushes from a hardware store, ground down to fit into the fan.

 

[JRA2000TL]

I disconnected the 3 prong connector and used a volt meter to check power at the harness with the car running. Took some trial and error to find which was the power and which was the ground, but once I found it, I was getting roughly 13.84v.

As soon as I plugged the fan back in w/ the car running, it kicked on and ran. I drove the car this morning and the highest the temp level got was between the N and the O. This afternooon on the drive home (when it's hotter outside), it will get to the N or between the N and the red, but never into the red. The car shouldn't run this hot though.

 

[NotSoSlowSHO]

How do you know?

Unless you have an actual gauge on it, you are only guessing.

Heat does weird things. The temp sensor might be near the end of its service live, fan might be turning slightly to slow due to worn brushes, wiring/contacts might be corroded effecting the flow of current....

By the way, I totally forgot that Gen 2 fans had 3 prongs. They are 2-speed fans right? Maybe the HIGH speed isnt working.

 

[93rev2sev]

The coolant temperature sending unit may be your culprit, but I'd keep looking for the missing pigtail and then pull codes to see if the fan kicks on like it's supposed to when puling codes.

 

[JRA2000TL]

I replaced the coolant temp sending unit (the 1 wire one to the gauge), I know there's a second one in the back that has two wires also. I haven't done anything with that one. I spent a long time last night looking for that missing pigtail and was unable to find it, tracing every wire loom with every plug. It was frustrating.

 

[K-Dawg]

The fan on my 93 used to kick on when the needle got almost to the H. Before the convention, I replaced some grounds on the car, and now it comes on just above N. Point is the factory gauge doesn't mean much. Also, with the coolant issues you've been having, you may have some air in the system that is throwing your gauge indications off.

Turning on MAX AC should turn the fan on in high speed.

 

[ShadetreeSHOguy]

Turning on MAX AC should turn the fan on in high speed.

This.

This should kick the fan on high speed mode. IF it does not. Test the fan directly with 12v. if that kicks on that way. Id suspect the CCRM or the coolant temp sensor. Not the one you changed at the meet. the one on the back side of the motor. The pita one, lol

 

[93rev2sev]

I replaced the coolant temp sending unit (the 1 wire one to the gauge), I know there's a second one in the back that has two wires also.

I think that's the one that tells the computer to turn on the fan for extra cooling.

 

[St Louis SHO]

I personally think the fan motor is dying.

From what he told me last night, the fan sometimes runs, sometimes doesn't. He also stated that the fan does not run with the AC on.

 

[93rev2sev]

Easy way to tell...take your cordless drill battery and jump it directly to the fan motor.

I have used 14.4 dewalt packs for this...but I'd recommend a 12v pack. I don't think an 18V pack would hurt anything, but use a 12 is you've got one.

 

[JRA2000TL]

I'm dumb...my fan is working. Apparently I was looking at a stationary part of the fan. I saw a part number on what I thought was the fan hub that turns and didn't ever see it move. The fan comes on when the a/c comes on. It never gets to the red or the H but can get as high as the top white line or go just above the N.

Since it's not overheating, I will look into it more eventually, but for now I'm going to drive it as-is. It has been staying mostly at the O but varies. It's not boiling over, so it's fine for now.

 

[ShadetreeSHOguy]

Apparently I was looking at a stationary part of the fan.

 

[Shovert]

It happens to us all. Get the car good and warm. Turn off the ac and make sure fan is
running. The AC part jumps out the engine control part of fan. Just need to make sure it
works from the computer part and the IRCM. The 2 wire sensor is the ECT sensor. I have some links on this sounds common to the eec-iv computer I know with the Mustang. Bear with while I learn a little on the SHO and if I am wrong correct me quickly. Maurice
http://www.rothfam.com/svo/reference/sensors.pdf
Here is some info on the IRCM and what a guy did to repair them.
http://jr.rustecat.com/articles/ircm/assem.html

 

[kevinspann]

Dude, that thing is loud as shit, how could you not hear it?

 

[SHOZ123]

The Hi speed fan is controlled by the AC. The low speed is controlled by the PCM via the ECT.

 

[tool88]

you could temporarily disconnect the electric temperature sensor and your fan will run constantly while your driving. i know it isnt a solution but if your worried about possible overheating it will keep the engine cool if you have a long haul

 

[JRA2000TL]

I think for the most part it's ok. The car isn't overheating, but it's just been running warmer than normal. On my morning commute it gets to about the O. During the afternoon commute when it's hotter outside and traffic is more stop and go, it can crawl above the N but not to that top white line or into the red.

I also just replaced the t-stat since I did the upper radiator hose. Maybe I opted for the higher 195* vs 180* (or whatever the #s were), so maybe that's why it's doing that.

I've driven the car all week w/o overheating.

 

[93rev2sev]

It's been my experience that when there's an actual cooling problem...the needle shoots quite a bit higher and will be in the red in about 2 minutes.

Do check your grounds and perhaps take a whack at that rear coolant sensor. There's a 1 inch or 15/16" wrench requirement...can't really do it with an adjustable wrench.

 

[tool88]

I'm sure it is 1" i just had a similar problem where my fan wasn't coming on at all till i replaced the sensor.