Hey all, my '91 740 has recently had issues with the climate control. I just recharged the AC system and was able to receive cold air and even hot air when I wanted it.
So no problems occurred for about three weeks, until yesterday. My AC quit working and I thought that the freon that I put in leaked out. I had pressure in my AC lines, but the compressor would not function. First thing that I did was look at the fuses and found a very surprising sight. The #16 fuse, the climate control fuse, has melted and part of the fuse board where the #16 fuse plugs into is partially melted, but still functional. Next thing I did was unplug the power to the AC compressor and tested the climate control with a circuit breaker wired into the fuse. The circuit breaker tripped, so I then turned the fan switch from high (5) to low (1) with the AC compressor plugged back in. The circuit breaker did not trip, so I plugged a new fuse into the plug and it didn't heat up like before (which I didn't mention earlier).
So with that said, the only thing that I can really point to is the blower motor may be drawing too much amps. I only need help on how to get the blower motor out so that I can clean the trash out and possibly replace the motor if it's too far gone.

 

the ventilation blower is below/behind the glovebox.

there's also a resistor pack on the outside of the ventilation airducting near the fan, the fan speed switch 1-5 is wired to this resistor pack, such that speed 5 goes directly to the fan motor, and speeds 4-3-2-1 each add one more resistor to the circuit to slow the fan down. this resistor module has been known to cook with age and fry itself, but that usually causes the fan to not work at any speed other than 5, which doesn't sound like your problem.


here's the fan behind the glovebox...

 

Thanks. It would also be a helpful if someone had a step-by-step that was better than the one in the Chiltons book that I have. Chiltons doesn't exactly have pictures for my car (I'm a visual learner more than anything else).

 

the chilton books are basically awful.

you'd be more likely to find a youtube howto or something online. 740 and 940 are virtually identical

but this is a pretty simple job. take out the kick panel, take out the glovebox, and its right there. the motor+fan assembly unbolts from the bottom of that grey tub you see in the picture.

this is the replacement fan+motor, its a direct fit.
https://www.fcpeuro.com/products/vol...80-940-3537854

 

Thanks again. I'll see about ordering one if needed when I get paid.

 

note there are other cheaper replacement fan/motors, brands like Meyle. AVOID, they are chinese junk. the VDO one I linked is pretty much identical to the factory one. also note earlier 740s used a different motor.

 

Got it. Ordered the part from FCP. Should be here some time next week.

 

OK, didn't have time until now to work on the car. I opened the box for the blower motor and received a blower motor, wires for power, screws, a new rubber seal, and some plastic bracket in which I believe attaches to the car so that the motor can be attached. Can I just use the old bracket on the car?

 

Plus the directions that came with it said that I will have to cut the new bracket with a hack saw and drill holes into the car. Is that really necessary? I took the plastic housing that went over the old motor and placed it on the new one and it seemed to fit just fine. It doesn't seem necessary having to drill and cut just to get it to fit when it looks like it will fit already.