(Hi guys. I'm new here.)

I have a 1994 850 Turbo sedan. Yesterday, 15 minutes before leaving work, I went out and started my car to warm it up. I'm in the blizzard-stricken Northeast. When I went out to leave, I realized the heater fans weren't blowing. On the way into my mechanic this morning, I noticed that the rear defrost also wasn't working. The previous morning, both were working fine.

It seems like my mechanic only fixed the fans, and the rear defrost seems to still be non-functional. I'm going to take it back in, but could the simultaneous failure of both these components be symptomatic of a larger electrical problem?

Thanks.

 

Check fuse #32 - it controls the ECC and slow speeds of the blower. Also check fuse #12 for the rear defrost. Both are 10A. Check fuse #5 for speed #4 on the blower... Not sure if you noticed but did you see any blinking lights for the AC and REC lights when you started up? If your ECC computer senses a fault they will blink for 20 seconds or so. Can you get the blower to work in manual mode? You can check for ECC codes by jumpering to pin 1 on the B diagnostic unit.

 

Thanks. I checked the fuses before I took it in, and they looked good. Mechanic changed out the blower motor and it's going strong now.

The AC/REC lights have been blinking for at least a year, without any apparent issue, and continue to blink after the new has one been installed. I'll check the codes this afternoon. Did my mechanic neglect to manually clear them, or does this indicate there's still a problem somewhere?

Regarding the rear defrost, the mechanic told me it was probably more trouble than it's worth to deal with. He had me check that the connections were intact across the back window, and that there were no obvious frayed wires hanging out around the edge of the window. Otherwise, I'm getting into replacing the back window and perhaps the wiring. Any thoughts there? It's a new mechanic that I'm still feeling out.

Thanks.

 

You should be able to clear the codes following the standard 850 view all procedure - check out this URL www. volvotips.com/index.php/850-2/volvo-850-s70-v70-c70-service-repair-manual/ for a list of codes. As to the rear defroster, test to see if you have voltage at the rear window connector. If you do, it may be the element itself, or the connection. If not, then it may be the switch so check voltage into and out of the dash switch