I posted the following in January 2016 and am including it in this new post to provide past history:
“The air conditioning blower motor stopped working this past summer (worst timing ever). I took it out, put it back in, and it worked again for a day before dying for good. So, I ordered a new one and replaced it. The replacement was working fine for about 5 months, but it then began exhibiting the same problem as the original: it wouldn’t come on until after I’d been driving for a while. The new unit never made any unusual noises while running (the old one got noisy just before I replaced it), but now it isn’t coming on at all. I find it hard to believe that the replacement blower motor has failed after only 5 months. What else should I check?”
The problem has intermittently resolved itself for a few weeks or months only to eventually return. Giving the glovebox a good whack or driving over a pothole sometimes got it going again, leading me to believe that there might be a wiring issue. After it stopped this last time, I finally followed all of the suggestions to the previous post: I checked the fuse (good), checked the relay (good), and replaced the resistor. No change.
I reluctantly took out the blower motor today (I’m tall with broad shoulders and tend to get stuck under the dashboard, so I hate working on this). What I discovered was that the blower motor worked depending on how I positioned the power wiring that plugged into it. Strangely, the tighter the wiring was stretched, the more likely the motor was to blow at full speed. The two wires leading to the connector were wrapped in some electrical tape and a short piece of heat-shrink tubing, so I removed that to see if I could spot any crimping or exposed wire. I couldn’t, but now I can’t get the blower to spin at all.
Unless I’m missing something, it seems that I have faulty wiring leading to the blower motor. From looking at the tangled mess of wiring that the two wires powering the blower motor come from, I don’t see any easy solution if the wiring needs to be replaced. Any suggestions?