1994 850 Heat Has slowly ceased blowing. Heater Core? Or...?

Post by **cn90** » 02 Jan 2019, 22:11

Thermostat, use only Wahler, about $15 with gasket.

Heater Core, search forum for the ebay HC from Estonia, about $40 or so.
I installed it in my 1998 S70.
Great HC. Make sure you use Volvo O-rings.
Also, if you want to bypass the firewall coupler, search for my DIY in forum.

greg850r · Post by **greg850r** » 08 Jan 2019, 20:40

R&R heater core, fan and resistor all share half of the work in common so I would do all 3 at the same time. Once you are in there do them all.

JamesDinCT · Post by **JamesDinCT** » 10 Jan 2019, 19:24

Thanks everyone, esp. Sommerfeldt! Ugh I’ve been stalling on this fix for some reason. Cn90 you mentioned a thermostat. You think I need to replace that as well? Also is there any chance that it’s just my resistor and not my blower motor? Would it be sensible to do that first to see? I’m sure the Heater Core is shot too but is it possible the motor isn’t and just the resistor is bad or no? Not sure if I want to keep putting money into this car as much as I love it, so reallllly wanting to keep my price as low as possible.

JamesDinCT · Post by **JamesDinCT** » 10 Jan 2019, 21:08

Oh yeh and what about the relay? No one mentioned the relay. Based on some of my reading it seems like a bad relay can also cause some of my issues. I’m sure y’all would know better than me. Just curious.

Post by **abscate** » 12 Jan 2019, 04:15

With the report of the fan failing in stages of fan speed, that does sound more like the resistor or power driver than fan itself. Internet diagnoses are 50-70% reliable. People with the expertise to give you a firm diagnosis by looking at the job get the same bucks as fixing it...$100 an hour or more. Not really anyway of escaping that. If you go cheap and replace all those parts with cheap options I’ll guess you will spend the same as a paid fix of just the broken parts. The downside is, you won’t learn a new skill.