Two new Blower Control Modules (BCMs) failed, back to back

[mp-rdp]

Dear Marauder Community,

After the blower motor ceased to function on my '04, my mechanic did some testing and determined the the Blower Control Module (BCM) failed and needed to be replaced.

He did the job and returned my vehicle. Everything seemed fine. I turned on the A/C, was able to adjust fan speed up and down. A/C air was pushing from the front vents, just like before. Put on the defrost function. Air pushed out of the defrost vents. In other words, all in order.

But about 10-20 minutes later, the often-repeated scenario from previous threads happened: Fan speed began to increase. I couldn't lower it. Then max fan speed. I pushed off, no effect on fan speed. Just max. Plus, I couldn't control where the air was being pushed from (defrost, front vents, floor vents).

Brought vehicle back to my mechanic and explained. He did some tests and determined that the BCM failed (?!). He made a warranty exchange and put a new BCM in. He tested the climate-control system. So did I, after I picked the vehicle up. All normal (fan speed, where air pushed from, etc.).

But, again, after 10-20 minutes of use, the fan speed increased and could not be controlled anymore. This time, however, I could control where the air was being pushed from.

Right now, my mechanic is at a loss about what is causing the BCM to fail.

Any insights? I see some users mention bad soldering points on the BCM board.

Note that the two BCMs installed are not from a Ford dealer. My mechanic described them as not cheap-os; kind of like Ford, but not Ford.

Thanks.

[RoyLPita]

How about the roller switch in the EATC head?

[mp-rdp]

Thnx for the reply. I can mention the roller switch to him.

When the system was working, I could control fan speed both on the steering wheel and EATC head. With BCMs failed, neither steering wheel nor EATC roller head worked in reducing fan speed from max.

[fastblackmerc]

Dear Marauder Community,

After the blower motor ceased to function on my '04, my mechanic did some testing and determined the the Blower Control Module (BCM) failed and needed to be replaced.

He did the job and returned my vehicle. Everything seemed fine. I turned on the A/C, was able to adjust fan speed up and down. A/C air was pushing from the front vents, just like before. Put on the defrost function. Air pushed out of the defrost vents. In other words, all in order.

But about 10-20 minutes later, the often-repeated scenario from previous threads happened: Fan speed began to increase. I couldn't lower it. Then max fan speed. I pushed off, no effect on fan speed. Just max. Plus, I couldn't control where the air was being pushed from (defrost, front vents, floor vents).

Brought vehicle back to my mechanic and explained. He did some tests and determined that the BCM failed (?!). He made a warranty exchange and put a new BCM in. He tested the climate-control system. So did I, after I picked the vehicle up. All normal (fan speed, where air pushed from, etc.).

But, again, after 10-20 minutes of use, the fan speed increased and could not be controlled anymore. This time, however, I could control where the air was being pushed from.

Right now, my mechanic is at a loss about what is causing the BCM to fail.

Any insights? I see some users mention bad soldering points on the BCM board.

Note that the two BCMs installed are not from a Ford dealer. My mechanic described them as not cheap-os; kind of like Ford, but not Ford.

Thanks.

Use a genuine Ford BCM. They are about $75.00 or PM me for info on an upgraded one.

[RoyLPita]

See if the blower motor is drawing too much power.

[mp-rdp]

fastblackmerc and RoyLPita, thnx for the suggestions. Adding them to my list.

[RoyLPita]

When the BCM went south on my MM, the BCM, the blower motor, plus an updated harness were replaced together. It has worked flawlessly since then.

[fastblackmerc]

When the BCM went south on my MM, the BCM, the blower motor, plus an updated harness were replaced together. It has worked flawlessly since then.

Do you have the harness P/N?

[RF Overlord]

My mechanic described them as not cheap-os; kind of like Ford, but not Ford.What does that mean? They're either a genuine Motorcraft replacement part or they aren't. Many aftermarket parts are crap, even if they aren't cheap.

A former member (RIP SC Cheesehead) had the same issue...it was a problem with the electronics in the EATC head unit.

[RoyLPita]

Do you have the harness P/N?

Here are the parts that were replaced:
blower motor controller 8W7Z-19E624-A
blower motor 1W7Z-19805-BA
jumper harness 4W7Z-14A411-B

Do I need therapy for knowing my (former) MM's VIN off by heart?

[mp-rdp]

Thanks to you guys for your time, observations, suggestions, and opinions.

My mechanic decided to install the Motorcraft BCM, along with a new wire harness.

I picked up the vehicle this afternoon and drove it around for some time. Ran all the functionality tests on the EATC, and all is working properly.

If any further issues arise, I'll update.

Here's a front and back picture of the second fried, non-OEM BCM (w/ part number):


http://i1321.photobucket.com/albums/u543/mp-rdp/IMG_1430_zps38c471fb.jpg

http://i1321.photobucket.com/albums/u543/mp-rdp/IMG_1431_zpsb6258b43.jpg

[PonyGuy]

Just for what it's worth, I had a similar problem with my 2004 GMQ. The factory BCM died, and I replaced it with one from AZ that was guaranteed for life. Well, "life" was about 4 months. However, I kept the factory original controller, and opened it up and looked it over. There was a burned connection on the circuit board, so I soldered it back together, reinforcing it with some copper wire. I returned the aftermarket controller and got a refund, and put the repaired factory unit back in and it's been functioning perfectly for almost a year now.

Here's the faulty unit. You can see the burned connection.
http://img.photobucket.com/albums/v313/ponyguy/P7210024.jpg (http://smg.photobucket.com/user/ponyguy/media/P7210024.jpg.html)


Here's the repaired unit. Works perfectly now.
http://img.photobucket.com/albums/v313/ponyguy/P7210028.jpg (http://smg.photobucket.com/user/ponyguy/media/P7210028.jpg.html)

[J-MAN]

Here are the parts that were replaced:
blower motor controller 8W7Z-19E624-A
blower motor 1W7Z-19805-BA
jumper harness 4W7Z-14A411-B

Do I need therapy for knowing my (former) MM's VIN off by heart?

Whatever you have I hope it's catching. :D

[UncleLar]

I replaced one that failed and it failed again in a matter of months.I was told then to replace the blower motor when replacing the controller. I got a "beefed up" controller from a member here,installed it and replaced the blower motor at the same time It's been fine ever since.