Climate Control Redux

Hey everybody! I've been gone a few weeks. Between the flu, my new job, and the vagaries of my standard issue life, I've just been super busy.
Unfortunately, a new electrical bug (Is my 98' LSC the super rare "Built by Jaguar in Coventry Edition"?????) is the impetus for my timely return. Here's what we know:

#1. I was doing the "wiggle fix" for months until about three weeks ago when I finally got down there and did a more permanent (I thought at the time) repair of cleaning and crimping the contacts. After that, All was well till now.

#2. Three days ago the blower just cut out. I was driving around, stopped at The New Jersey Home for Cranky Middle - Aged Women, and when I came back out and restarted the car, the blower motor refused to work. I was a little annoyed, but not worried, thinking it was the same old thing. I was wrong.

#3. The refurbished electrical connection I did last time between the little box thingy mounted under the dash (I have dubbed this little box thingy the "Blower Motor Speed Control", or BMSC, even though Im pretty sure thats NOT what it's called, or what it does. It shall be hereforth referred to as such.) which is in between the CC head unit and the Blower Motor itself, is still tight and intact. Also, obviously. the "Wiggle Fix" did not work.

#4. The CC self-diagnostic that is accessed by pressing Off and floor simutaneously, then Automatic within 2 seconds will not work.

#5. The blower motor will spin when I put a 9 Volt battery directly on its contacts. The Motor is not the problem.

#6. I have 11.6 volts at the end of the Blower Motor electrical connection (the black and orange wires that connect directly to the motor itself). This means that I am at least getting voltage after the suspect BMSC, although the illustrious personages of Steve and Driller tell me that this doesn't mean I have current as well, I am not actually smart enough to discern this distinction, and therefore have chosen to ignore it.

#7. The BMSC fell apart to reveal moderate corrosion which is illustrated in a picture that I sent to Driller from my cell phone. I am also not smart enough to know how to post said picture here, so hopefully JP can do it when he reads this.

#8. I reconnected everything, although I did leave the glovebox and lower dash trim dissassembled, cleaned the BMSC circuit board with electrical contact cleaner, and left it sitting on my passenger side floor. (It is still electrically in line with the blower and CC head unit{Which is fully operational BTW} and just hanging down by the wires onto the floor)

#9. Driller, who so graciously gave me part of his Saturday afternoon by phone, and I concluded from this picture that the BMSC was DOA and therefore the culprit in this issue. I decided that I must then search out a new BMSC, and began to make calls. No luck with that so far. You might be thinking that this issue seems resolved, but wait...... there's more!

#10. On my way home from the previously mentioned new job, (which SUCKS, in case you were wondering) the blower motor magically began to work! I had left my CC set to Auto 78*, where it always is, in the hopes that this very thing might happen. I didn't hit a bump or pothole that might have momentarily reconnected a short, as a matter of fact, I was stopped at a light the first time it came on. It came on 4 or 5 times throughtout the ride home, staying on for the longest of those times for maybe 15 seconds, and the shortest maybe 3. The thing is, that circuit board on the BMSC is totally effed up. (Hopefully Driller has posted that picture so you can see for yourself.) Even though I did clean it and attempt to get some of the corrosion off, I didn't think that solid-state electronics could come back from this kind of thing. I'm under the impression that once they are in this state of disrepair, there's no coming back. Maybe I'm wrong? So here we are, now IDK if this BMSC is really the problem or if it is something previously unconsidered. All I know is that even though my baby is running great, having no blower motor is a serious issue in my book, and I would love some insight on what could be wrong. Also on who has a new BMSC if this is confirmed as the problem. I don't want to order a new one from Lincoln, (if it's even available) and then find out it's not the problem cuz they most likely will not allow the return of a special order electrical item. Happy Thinking!!!!!
 
Did you manually test all the speeds of the fan? Does it work in each position?
Solid state electronics behave differently under various thermal conditions that may cause the strange behavior you are having.
 
Here's the pic. I believe it to be bad just from physical appearance.

The only thing that may be the answer is the EATC may be at fault since it does not complete a self-test? I hate to see you throw parts at it but I'm unsure what at this point could be the alternative without scanning for codes. Perhaps a friendly dealer could scan for codes without charge?

What if you take out the circuit board and examine the other side?
 

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If nothing else, there is high resistance on the back (actually the front) of that circuit board at various components.... It MAY be brought back to life by removing the board and re-soldering all the joints that look affected, but I think I would just toss it and replace it with a known good one.... Jamie prob has 20 ! What I WOULD look for is the water leak in the dash that started this whole problem.
 
I don't know how to manually test all of the fan speeds. All I know is that is does work with the 9 volt battery. I have a code reader (x-cal 3) that i bought from Lonnie. I haven't used it cuz the CE light hasnt come on. Would there still be a code w/o a CE light?
I just took it out of the car and I am going to take it apart and clean it as well as I can. I mean, it's alredy broken, so I can't hurt it more. I'm gonna take it apart and look at the back now. Ill keep you posted.
I haven't the slightest Ides how to find this (possible?) water leak. IDK is there is even one. Nothing else under there is wet and no other connections are corroded that I could find.
 
More info...

A/C Blower Motor Speed Control

The A/C blower motor speed control (19E624) is located under the A/C evaporator housing, forward of the blower motor (18527).

The function of the A/C blower motor speed control is to convert low power signals from the electronic automatic temperature control module to a high current, variable ground feed for the blower motor. {emphasis added}
A/C blower motor speed is infinitely variable and is controlled by the electronic automatic temperature control module software.
A delay function provides a gradual increase or decrease in blower motor speed under all conditions.

Did you know there is a Blower Motor Relay on the Gen2? I didn't. It is to the right of the glovebox and looks to be a typical cube relay plugged into a relay harness connector. It is likely mounted to the right side cowl panel behind the kick panel.

You will only get generic codes from an SCT or retail scanner. No component specific codes will be read from the OBDII. The New Generation Star (NGS) Tester, P/N 418-F048 (007-00500) or equivalent is required for diagnostic scans of the climate control system.

If the concern remains after the inspection, connect the New Generation Star (NGS) Tester to the data link connector (DLC) located beneath the instrument panel to perform the DATA LINK DIAGNOSTICS test. If the NGS responds with NO RESPONSE/NOT EQUIPPED for the electronic automatic temperature control module, go to Pinpoint Test A. If the DATA LINK DIAGNOSTICS test is passed for the electronic automatic temperature control module, retrieve the continuous DTCs and execute the Self Test Diagnostics for the electronic automatic temperature control module to retrieve the current DTCs. This is the only way DTC's related to the ECT and vehicle speed can be retrieved. {emphasis added}

I know you have tried the self-test, but for those who do not know, here are the self-test procedures:

Electronic Automatic Temperature Control Module Self-Test

The EATC module self-test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A NGS tester must be used to retrieve these concerns.

The EATC module self-test will detect concerns in the system control functions and will display hard diagnostic trouble codes (DTC) in addition to intermittent diagnostic trouble codes for concerns that occur during system operation. The vehicle interior temperature should be between 4°-32°C (40-90°F) when performing the self-test. If the temperatures are not within the specified ranges, false in-car temperature sensor DTCs will be displayed.

The self-test can be initiated at any time. Normal operation of the system stops when the self-test is activated.

To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.

If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.

If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.

To exit self-test and retain all intermittent DTCs, push the blue (cooler) button. The control will exit self-test, retain all intermittent diagnostic trouble codes and then turn OFF (display blank).

To exit self-test and clear all diagnostic trouble codes, press the DEFROST button. The vacuum fluorescent display window will show 888 and all function symbols for one second. Then, the EATC control assembly will turn OFF (display blank) and all DTCs will be cleared.

Always exit the self-test before powering the system down (system turned OFF).

Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.

Specific causes for no blower motor operation:

  • Circuitry open/shorted.
  • Blower motor.
  • A/C blower motor speed control.
  • Blower relay.

You tested for voltage on pin 3 and did not detect a short. You then tested the BMC by grounding pin 3 and nothing happened. So, in my diagnosis, the BMC is DOA or MAYBE the blower motor relay is bad. Of course, I still do not understand why the EATC would not self-test. But even if it did, from what I read in the manual, it will NOT indicate a faulty BMC.

I would find that relay and replace it. If nothing then, I would get a BMC from Jamie or a junkyard. I looked for one in my parts stash and did not have any.

You could con Steve into swapping his with yours for a test? :fart
 
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