Elvis, this is a fantastic writeup and saved me money and grief. I have a couple of comments:
1. BLOWER STOPS WORKING COMPLETELY. This repair also works in at least some cases when the blower STOPS WORKING ALTOGETHER. A lot of the web-based commentary seems to imply that the FSU replacement only fixes blowers that are intermittent, or that have speed problems. In my case, the blower stopped working at EVERY SPEED. It was just like it was switched off. I followed all the commentary and tested it at all speeds -- NOTHING!! I was really afraid then, that the blower motor was kaput, and not the FSU, based on all the comments. But I decided to try the FSU first, and I'm glad I did. For $52 bucks, free shipping from autohausaz, it was really worth a try.
2. CONTORTION. For me to do this repair, I had to lower the passenger seat down as low as it would go, and move it as far back as possible, into an almost bed-like position. Then I climbed into the seat backwards, with my feet toward the back of the car, my body upside down, so I could get my head and arms underneath the dash, facing up towards the FSU. It's very close in there, but even a monstrously large person like myself (6'2", 280 lbs) managed to get in there with some difficulty. If you have a small, thin person in your family who is very flexible, you may want to engage them for the removal and installation of the FSU.
3. FUSES. Of course, the first thought is to check the fuses. Once the "easy" ones in the glovebox are checked and found to be ok, the thought is that Fuse 75 or 76 might be to blame. They are big 50 amp fuses that are located in a very difficult place, behind the glovebox. I know there is a lot of commentary out there about how to remove them. But REPLACING them is something else altogether. No one mentions that there is an aluminum brace that is in the way. After diddling around for a long time, I found that the only way to REPLACE those fuses is to jam your hand in back of the aluminum brace by force, and punch the fuses in from the top. The aluminum brace will move enough to let you get your big fat hand back in there if you use force. Of course, in my case, all of this was wasted, since the fuse was not the problem. However, to get to the FSU, it really helps to have the glovebox out of the way anyway, so all the effort was not wasted.
4. FSU REPLACEMENT. Make a mental note of the orientation of the FSU as you take it out. There is little space to work down there, and it is very difficult to keep turning the new one around trying to fit it back in. Plus the new one is not exactly the same shape as the old one. I printed out a picture of the FSU in place from Elvis' DIY and brought it with me out to the car. That really helped. Nevertheless, be prepared for some jockeying to get the old FSU out, and the new FSU in -- the only thing that I was concerned about was damaging the very soft prongs in the new one while installing. Luckily that turned out to be not a problem.
5. SOFT PRONGS. I should note that the new part, from BEHR (the old one was made by VALEO
) had very soft prongs. The old one's prongs were very hard and could not be bent, but the new ones were very bendable. In fact, I thnk I accidentally bent them a little while fooling with it. I did not know whether this made a difference, but where they touched each other, I bent them back so that they did not touch, and were aligned in neat rows. Maybe this made no difference, but I didn't want to take the chance.
In my case, as soon as I replaced the FSU, everything went back to normal! It's like magic. I was dreading having to disassemble half the car and replace the blower motor -- but that won't be necessary, thanks to our friend Elvis! Really appreciate what you have done here for all of us.