EATC\blower motor controller problem

[Russo]

Hey all, sorry for the long post.
My blower motor in my 98 quit on me a few days ago. Doesn't even spin up, no air coming out at all. The EATC unit looks to be functioning fine. I ran the self-test, and it didn't throw any codes at me. It's starting to get really hot and humid here, so I need to get this fixed ASAP. I did check the connections as per the intermittend blower motor fix tech article, and that didn't help any.
Here's the deal: I ran some pinpoint tests from the service manual, namely PINPOINT TEST G: THE BLOWER MOTOR DOES NOT OPERATE, to eliminate some of the possible culprits. Step by step - the blower motor speed controller (pin c210-1) is getting enough voltage (12V+), so it's not relays\power distribution. Next, I bypassed the speed control by wiring the blower motor directly to 12V - the motor ran fine at full speed, so the blower motor itself is not the problem. The next step is to check the EATC blower speed signal, it says "Press the override button for MAX A/C operation and adjust the blower motor speed override control to maximum. Measure the voltage between the blower motor speed control connector Pin C210-3, Circuit 184 (T/O) and ground. Is the voltage greater than 4 volts?
Yes - REPLACE the A/C blower motor speed control. TEST the system for normal operation." Here's where I got confused. When I checked with a voltmeter, the voltage at the highest speed setting is 0, the lower I set it, the higher the voltage gets, but it only gets up to about 0.05V. What is the normal operating voltage range here? If the voltage is less than 4 volts, it gives directions to check continuity in the speed signal wire, and if there's no opens and shorts, it says the EATC module needs to be replaced. So my questions are: what are the normal operating voltage ranges for the blower speed wire, and the blower motor itself? I checked the blower motor speed controller output, and it puts out about 9.8V to the blower motor, no matter what the speed setting is. I guess that's not enough for the blower motor to turn on. Is there a place in the service manual where I could find those specs?
Thanks for your help.

 

[GMAN]

Ah the wonders of the Tech Articles.

Click Here

 

[Russo]

That was the first thing I tried, but it didn't work..

 

[Frogman]

I'm depressed now.

Russo did everything he could, detailed what he did, (he didn't just jump on and say "My blower motor quit,what's wrong?")and now I can't help him because I haven't dealt with the blower motor on my 98 yet.

Maybe next time, Russo.

 

[mrzeee]

My tech is doing some research and Ill get back with the diagram after he gets back to me.
max

 

[mrzeee]

blower

The tech says; you say you follow the directions till you got to test for continuity and dont say if circuit 184 is has 4 volts or is good. Do you say you have less than the req 4 volts? if so you can test pin 9 on the eatc head, the other end of the #184 wire, and not see 4 volts the head is bad as the directions say. if it is 4 volts then the #184 wire is bad or the controller is bad. He also said that ford has no reason to know what voltage does what because of the pinpoint testing..it is not needed. just the testing for the 4 volts at c210 and 184, on this step.
As the step says more than 4 volts, after you "press the o/ride sw for max a/c and adjust speed control to max", replace the speed control then test for normal operation.
You can sometimes tap on the speed control and get some function and confirm the control is bad but that is NOT a valid test.

Do you have this diagram??

Max

 

[Moes8]

WOW MAX!!! you truly are awesome,that you would take the time to post a repair/test tip is incredible.

Thank you

 

[mrzeee]

Thank you for the kind words. I have to give the credit to the tech that did the research without which I could not have done it. I just hope it helps and the concern gets resolved.
max

 

[Russo]

I fixed the problem. First of all, I'd like to thank Max and others for taking their time to help me out with this. The problem, apparently, was with the blower motor controller. I started off with chasing any problems with circuit 184 (I used the same diagram that Max posted). The circuit checked out fine, though I still wasn't seeing anywhere near 4 volts on it, no matter what the setting on the thumbswitch was. Then I stumbled on a thread about a towncar blower motor problem http://www.lincolnvscadillac.com/showthread.php?p=75705 and the fix here - http://www.lincolnsonline.com/tech/00062.html

I figured I had nothing to lose, so I took the controller apart. The insides were covered with green and blue corrosion-like crap. I grabbed a small screwdriver, and cleaned it up a little bit, and then wiped out the rest. Went back to my car, really not expecting it to work, but it did. I suspect water got inside of it somehow, and that's what caused the problem. I checked circuit 184 again for voltage, while connected to the controller and blowing. It now shows between 2 and 4 volts depending on the speed setting.
Anyways, to make a long story short - don't be afraid to take the controller apart and look inside.
Thanks again for the help guys, I really appreciate it.