more data on cooling fans

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spent some time tonight testing the cooling system fan inoperation.

on the first pass of the test
koer test revealed the codes

53 - throtle position sensor wide open
81 - electro drive fan circuit failure **** bingo *****
65 - either overcharged or fuel system did not closed loop
38 - idle tracking switch open

so... we did some pokeing around and looked at the fuseable links - they all looked good - except when I took out onr of the 60 amp fusible links I saw it all burned up at the bottom - so I fugure hey I am onto something here.

Went to AZ and replaced the 60 A fusible link.
So here I am thinking that YAY - its fixed

So I ran the KOER codes again and this time something different happened - I got codes
65 - either overcharged or fuel system did not closed loop
38 - idle tracking switch open

Now I had two less codes so replacing the burned fuse link cured some of the codes.

NOW THIS TIME WHEN THE CODE READER WAS PLUGGED IN - as the engine heated up the fan cycled on and off normally. If I unplugged the code scanner the fan would no cycle anymore. I connected the code scanner again and the fan cycles on and off as it should.

WHAT DOES THIS MEAN - IS MY IRCM BAD - MAKE A NOTE HERE THAT without the scanned plugged in and even using the ac on max cool the fan (neither of them would come on). Put the code scanner back in and fans cycle as they should.


So - do I have a bad ircm - bad eec (etc sensor is brand new) - why would the code scanner make it work right.

Thanks in advance - I still need ideas and help....
 
If it worked during the self test then the computer is working, sending the correct signal to the IRCM. You know that the IRCM is working and the fusible link is good. You know that the fan motor itself is fine as are all the connections to it.

So deduction leaves you with only two possiblities. First, that the fan is working correctly and you have not heated the engine sufficiently to engage the fan. Remember, the fan does not come on until the engine reaches 220 degrees. Or second, the ECT sensor is not getting a temp signal to the computer. Nothing else remains at this point.
 
what should I test for voltage wise on the etc sensor - engine cold - then engine hot? to see if the reading changes??? also - I am curious why the fan would ccle on and off with the code reaer plugged in and not when it was removed??? Thoughts??? Could there be more since the fans (either one of them) never come on when the ac is turned on?????
 
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Does your AC work?
While my AC was out, the fan wouldn't come on with the dash AC control. Once 134 started entering the lines, the fan came on. All I getting at is my fan works with the AC only if the AC is charged and working.
 
well - the compressor comes on but does not blow cold - so maybe you have a point there about the low ac charge not making the fans come on... thank you.
 
MORE DATA ON THE COOLING FAN(S) NON OPERABILITY....

Today with the car cool - I used an ohm meter set at 1x to measure the resistance at the 2 prongs of the sensor - the resistance with the car cold was 100 - as the car heated us the resistance went to 150 - 200 then topped out at 250. So... I need to gues that the new sensor is working - right???

but when I first started the car when cold and with the etc sensor connector OFF the sensor - the fan came on at high speed and ran wile the engine was idling..... So, again I thought that the connector end may be bad because if this - or I also assumed that because the sensor connector was off that the computer was getting a reading to operate the fan. We let the car idle for a while then shut it off. we tried then to start the car with the connector off of the etc and the car would not start at all - it just would crank. I put the connector back on and the car would start - we tested this 3 different time and prooved that the car would not start with the connector to the etc removed when the car was hot.

Additionally once the car heated up with the sensor connector on - the fan would not come on. I added a can of refridgerant as mentioned above to see if the fans would start on max ac and they did not. So - I am still back to sq one. Any body else been throught this that can help me get this working normally?

H E L P ! ! !

Thank you
 
I am currently having similar problems. My low speed fan does not function with A/C and does not appear to be cycling with the car, only high speed. After recharging my A/C & watching the compressor work w/o the fan, I unplugged the ECT. This caused the fan to operate, as you described. I don't know what speed it was running at. I then replaced the ECT, thinking it was the problem. It did not fix it. Because unplugging the ECT caused the fan to engauge, I assume both the ECU & IRCM are functional, as they succeeded in engauging the fan. I now intend on testing both low & high speed motor windings by inserting wire into appropriate places of the plug for each speed & connecting to battery. This will tell me if my low speed winding has burned out.

If my low speed & high speed both work, I will be in the same position you currently seem to be in. W/O further knowledge or insight, my attention will be turned to the plug which connects to the ECT.

Goodluck; hopefullly one of us solves this!
 
How have you progessed on your difficulties? As you may know from following my thread, I have resolved a situation almost identical to yours. Even the high speed broke after probing the fan plug to check the circuits! lol.

The high speed turned out to be the plug, and the low speed was in fact the motor windings! Check the 3 wires coming off your fan motor. The all black wire on the right receptacle is ground, the black wire with a red stripe on the bottom receptacle is low speed positive, and the black wire with yellow stripe on the left recepticle is high speed positive.

I performed two tests. First, I tested the prongs coming off the male adapter in this order. The wire colors do not correspond, but obviously the prong positions do. Take a voltage meter or VTVM & ground one side. Then use the other side on both the bottom & left prong to check for voltage. The bottom prong should read around 12 volts when your engine is running with A/C on, and the left prong should read about the same with engine running & ECT sensor unplugged. If this test comes back positive, the problem is your fan, likely the low speed or even its plug! If you get no voltage from these connections, the problem lies elsewhere, either the IRCM, the ECU, or the ECT.

Since you mentioned it comes on when unplugging the ECT, this leaves two possibilities that I can forsee. Either you have a bad low speed relay in the IRCM, or like me, you have a bad low speed motor coil. Check like I said, & you will know.

Goodluck!
 
i have an escort with same prob i replaced coolant sensor and no luck i figured ircm but havent tried that yet, by the way my fan setting for sc stock was to come on at 228 about halfway on the guage with tuner i set low speed 200 high speed 210
 
Hey i have the same problem. no fan operation when i unplug the coolant sensor fan comes on i plug the sensor fan goes off , if anybody resolve this issue please advice me i turn crazy with this problem.
 
If your fan turns on during a KOEO or KOER test, that means your fan motor is OK. But the IRCM still may not be working or you have a bad ECT sensor.

If your refrigerant is low, the low pressure cut off switch will cut power to the clutch. And will not allow the fan to turn on with the AC buttons. So check your AC system pressures.

You can to test the AC circuit. by unhooking the low pressure switch connector and install a jumper in the harness. The fan should come on with the AC button pushed. If it does not turn on, there is a problem inside the IRCM. This is temporary fix so don't run your car with this full time. you will burn up your A/C clutch.


ECT sensor check:
*F K ohms
50 58.75
68 37.30
86 24.27
104 16.15
122 10.97
158 5.37
176 3.84
194 2.80
212 2.07
230 1.55
248 1.18
 
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