I recently bought an 84 500 SEL. I believe that makes it a 126w chasis. I love these cars but I'm new to them and having trouble diagnosing my problems. The main issue is the AC blower, the others are cosmetic or annoyance.

The previous (orriginal) owner had much of the AC system replaced less than 2 years ago, blower, dryer, compressor, some lines, complete rework basically. About a year ago she started having intermitent blower function. However, all she had to do was open the hood, slam it shut, and the AC would start working again. In Houston, TX AC is not a luxury, but a necesity, so I'm trying to diagnose and repair my problem...

I've done a little work diagnosing it:

1. The AC is cooling when the blower isn't working. Compressor runs, lines get cold, cold air 'seeps' out of the dash and vents.
2. I've sanded/buffed the fuse contacts (I know from Porsche's those fuses corrode and stop making good contact in humid climates).
3. I've read some boards and it seems there is a Blower Regulator, a Blower Switch, and possibly the blower motor that could be at fault. Or, wiring inbetween.
4. I leave the blower on high, but when it works it seems random to which speed the motor works at. And sometimes when I hit a good sized bump the blower stops, or switches speeds.

From what I've read, this is most likely the Blower Regulator or faulty wirring. I'm hoping someone could help me with 2 things.

1. Is there a way to diagnose the regulator vs wirring, vs anything else. Ie. standard diagnostic procedure for this circuit?
2. Where exactly in this vehicle are these parts located and servicable from?


My other problems are just creaky, CREAKY leather. The rear seat, and the vynil seams on the door panels make a lot of chatter. I'm curious what steps others with these cars have taken to kill this noise.

Thanks,

Trey

I hope I've provided sufficient detail, but if not, please let me know what is missing and I will locate it.

 

Update - Well I think I found the Blower Regulator, it is inside the dash and atleast visible after removing the glove box. Looking at it, it appears I have to remove the under pannels to service or replace it, and to do that will probably require me to stand on my head to do so.

Still looking for any diagnostic procedure to isolate which part is indeed at fault. I'ld feel better eliminating items rather than playing bingo mechanic till I replace the problem.

Is the climate control in it's own shop manual. I have the main 126 manual, and the engine manual (1200 or so pages total). I can find no mention to climate control anywhere in them =/.

 

had fan issues with my ac. the ac center vents would blow for abour 3-5 min then stop altogether. other vents worked. problem was a poor connection on the vaccuum hose. you might want to check this, especially if it falters when you go over bumps etc.. mech. friend told me if there is intermittent air blowing from vents it is usually a vaccuum leak. total non function indicates a blower motor (according to him).lol.

 

Your blower motor is most likely not the problem as it does indeed work (interm.)Most likely it's the regulator. They are infamous for failing. Easy DIY diagnostic would be to check the voltage at the regulator when you set different fan speeds to the blower on the climate control module. If you get different readings, then the regulator should be at fault. If you get no reading or insignificant changes then the push button control module would be something to look at. Good luck!