heater control help needed!

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woodrat
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heater control help needed!

Post by woodrat »

90 Legacy wagon. Ever since I bought this car three years ago, I've had heater control troubles. First time the heater stopped working, I went to the u pull its, and found a new heater control and installed it. Worked a little bit, and then back to no heater. Ignored it all summer, then in the winter, needed heat, so I went to the yards again, got another control unit, installed it when I changed out the leaky heater core, and all was well again. Had heat for a few months and then last March the timing belt went and I parked the car all spring and summer. Just replaced the timing belt a couple of weeks ago, and again, no heater controls. Then the next time I drove it, heater worked fine. Next day, no heater, next day, heater works fine. next day, no heater until I wiggled the fan switch. Then, no heater again, and no wiggling helps. Yesterday, perfect heater. This morning, no heater again.

Is there a relay for this system somewhere? I can't deal with no heater, and I can't keep sticking new controls in every couple of months, either. I have that 1990 version with the different plug, and they're not that easy to come by in the u pull its. I want to fix this silly thing once and for all, so I know that I will have a working heater anytime I need it.
1990 Legacy wagon, 340k miles, rusted out and retired to parts car status
1991 Legacy wagon, 232k miles
1994 Legacy wagon, 146k miles
1992 Dodge/Cummins W250 flatbed, 294k miles
1976 Mercedes 240D
1977 Mercedes 240D, 230k miles
subytech
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Location: Bellingham WA

Re: heater control help needed!

Post by subytech »

There is a main blower motor relay, its located up under the dash on the drivers side behind the fuse box. It has a bare aluminum case (silver) and is round. Its also a major PITA to get to. you can sometimes see it if you remove the small coin pocket in the dash and look back past and above the fuse box. I've replaced quite a fiew of these for similar issues. Hope this helps.
92 Legacy Turbo, 5sp MT, Early Large CC 20G heads, Ported custom clocked td04, Cobb catted DP, Injen SS 3" exhaust, Turbosmart MBC @ 10psi, Apexi 20g intake, custom FMIC, Fidanza 11lb flywheel, stock 05 WRX clutch
woodrat
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Re: heater control help needed!

Post by woodrat »

Thanks!

I figured out from the Haynes manual that there is a relay, but it wasn't exactly helpful when it came to telling me where it was. Guess I should have replaced that one while I had the dash out.... :?
1990 Legacy wagon, 340k miles, rusted out and retired to parts car status
1991 Legacy wagon, 232k miles
1994 Legacy wagon, 146k miles
1992 Dodge/Cummins W250 flatbed, 294k miles
1976 Mercedes 240D
1977 Mercedes 240D, 230k miles
rallyak
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Location: Anchorage,Alaska

Re: heater control help needed!

Post by rallyak »

I would look at the connector that goes to the fan swich. mine was doing the same thing and found the connector was melted not getting good contact.
Charles

90' White/Gray Outback DD workhorse (670,xxx) miles
92' Onyx Metallic (430,xxx) Wife's DD
68' Barracuda formula S 340 4spd coupe (ongoing project)
66' Mustang 2+2 4spd wife's (ongoing project)
woodrat
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Re: heater control help needed!

Post by woodrat »

Yeah, it turned out to be that yellow plug in the back of the control unit. Wiggle it and the fan comes on, wiggle it again and the fan goes off. I got it back in there in a position where it's currently working, but I'm not sure how long it will stay that way. Thanks for the help!
1990 Legacy wagon, 340k miles, rusted out and retired to parts car status
1991 Legacy wagon, 232k miles
1994 Legacy wagon, 146k miles
1992 Dodge/Cummins W250 flatbed, 294k miles
1976 Mercedes 240D
1977 Mercedes 240D, 230k miles
Legacy777
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Re: heater control help needed!

Post by Legacy777 »

Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
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