Hey Everyone,


I've been doing a lot of searching on this topic and wanted to do a quick check before I continue to throw parts at the problem.

1994 850 Turbo Wagon, Automatic Climate Control, 232k (I've owned for almost 8 years, since 140k)

Issue: About a month ago the blower motor stopped working, this was after years of slow decline where it would work but make noise, then after hitting a bump the noise would go away. At highway speed it would still allow cool or hot air into the cabin depending on the temp selection, but at a low flow rate. I pulled the codes and got a bunch (126, 417, 418, 419) including the failed passenger cabin temp sensor over the door which has been an issue for a while but hasn't affected the system noticeably.


Current status: Last night I replaced the blower motor (new OEM Behr) and blower resistor (new Volvo OEM) and still have no fan. There is 12VDC at the blower plug, and when you turn on the car the blower runs for about a second then turns off. I tried the blower with the car running, not running, all key positions and fan positions, no luck. I cleared and pulled the codes again with these coming back:

126, 417 (passenger temp sensor shorted, pass temp fan seized)
419 Faulty diagnostic signal from blower fan power stage

Next steps: From what I can tell the ECC control unit needs replacement but I wanted to see if there was anything else I may be missing. From my research the blower motor fails, it draws more current from the resistor which eventually fails, then at some point it takes out the ECC control unit. Not sure if this is accurate, hence me asking. I removed the ECC and haven't noticed any burned up smells but who knows.


Any tips would be greatly appreciated. I'll most likely go with a ebay ECC unit for $60 so I have something to work with this week.

Thanks,













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Zack 94' 850 Turbo Wagon (232k)