Need help with 91 560SEL ac blower - PeachParts Mercedes-Benz Forum

AgieDC · #1 09-13-2006, 12:48 AM

Fan blower is not working.

Have checked the following.

1. Main fuses not blown in main fuse box front left firewall.

2. Unable to confirm location of any auxilliary fuse to see if blown. I read that a 16 amp blower motor fuse is in line, but not sure where it is, and unable to determine from service manual.

3. Under passenger dash, removed covers and disconnected power supply to blower motor (3 prongs). Tested voltage from pushbutton switch and confirm that power does reach the blower at appropriate voltage ranges for low, hi, and auto fan settings.

4. Blower does not run. If run wire directly from battery to blower, it will run. If run direct hot wire to "red" wire in 3 prong connector under passenger side, keep everything connected together, everything runs fine, even varible speeds of fan blower. What does this mean?

5. How can I test blower, current regulator (N29) to see if working correctly or not burned out?

6. How can I test steps 8 to 21 (p. A29 in Service Manual) if I only have a multi-tester?

Stumped. ANy help is appreciated. Chris

david s poole · #2 09-13-2006, 09:39 AM

chris,your symptoms tell me that your main 30amp flat fuse is blown.it is in a black rectangular box with a lift up cover usually on the left shock tower.

AgieDC · #3 09-13-2006, 05:05 PM

David, I will check tonight, thank you. I know that there is a fuse tower just to the right of the main fuse box with a flip lid and a 10amp fuse in it, but not blown (next to the 12 pole module for the AC unit if that makes sense.) I will check on shock tower and report tonight. CB

Ferdman · #4 09-14-2006, 04:21 AM

Chris, the 30-amp strip fuses develop hairline cracks and appear fine until you remove them. Simply remove the 2 screws and closely inspect yours. New ones are .56 online or a couple dollars at a MB dealer.

david s poole · #5 09-14-2006, 01:43 PM

that link is for 140 car his is a 126

AgieDC · #6 09-14-2006, 03:27 PM

Have not had a chance to inspect yet. Thank you for comments and will let you know. CB

Ron in SC · #7 09-14-2006, 04:36 PM

If you are not gettting power to the 30 amp fuse under the hood it's possible that the starter switch is worn and it's not providing power to the fuse.

Just the other day my blower stopped working. It worked in the morning then I parked vehicle for about 1 hour and when I started itand drove for a while the blower did not work. I parked it again for a couple of hours and when I started vehicle the blower worked, and it's worked today so I can not do any tests until it stops again.

If you tested the prong for the yellow wire (that's what color it is on my 124), it's one of three that goes to the regulator and it has power and you know your blower works then the regulator is the problem.

AgieDC · #8 09-14-2006, 11:10 PM

David and Ferdman - how could I have missed the strip fuse. Well, at least I learned a great deal more about my AC unit. you were right, the strip fuse had a hair line crack. I will remove the old version and replace with a new 30Amp system. I really appreciate your comments which have helped me. If you are around Austin, TX, I will buy you a nice steak.

ROn - nice thoughts and appreciate them.

All - AC is working and back in order. I really appreciate the help.

Regards - Chris