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Howdy folks. 

Glad to see USMB back up and running. Seriously.

 

I write today regarding a lack of climate control. '87 GL wagon.

 

No venting. No heating. This and that.

 

I just replaced the blower motor resistor hoping that would do the trick.

It didn't. Though that's okay, the old one was shot. Corroded and bent. Had to happen anyway.

 

Now, where should I go from here?

 

Replace the blower motor? Test it? It looks as nasty as the resistor did.

 

What can I test to point me in the right direction?

 

Much thanks in advance.

 

 

 

 

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Is this a vacum operated system? I think it is (I may be wrong). If so then it is as simple as a vacumm leak somewhere between the manifold and the HVAC control. 

 

Are talking about the fan still not blowing or air not being redirected or both.

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If the fan is not working. Suspect the switch. The fan should at least wrk on #4 even if the resistors are blown out.

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@Nipper - Vacuum operated system, yes. I do believe so. Fan in inoperable. No blow on any setting or any speed.

 

@Miles - The fan is not working on 4, though the fan does look quite shotty. Took it apart just because.

The two springs with metal attached to them looked... Less than decent. - Where is the mentioned switch located?

 

@North - Fan brushes.... The.. The two metal guys on springs? They look... "Dented"

 

 

Thank you dudes. Greatly appreciate it, as always.

Edited by BoxerRebellion

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There is a relay in the fan circuit i do beleive. If the blower motor fuse is ok I would check that next.

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@Nipper - Probably solid advice.

 

Using a multimeter, I've got nothing coming from the blower motor plug. 20V setting. (Doubled checked the setting against the battery - 11.78.)

 

Alright, the next question would SADLY be, which fuse is the blower motor fuse. I have no diagram (cover) for the fuse box. Gah!

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AND.... THE RESULTS ARE IN.

 

The brushes on the motor were toast.

The resistor was visibly corroded and bent.

Figured I'd replace the relay to have a "fresh" system.

 

Multimeter testing the RELAY revealed -

 

KEY OFF - BL/RD-12.7v | RD/YL-0v | GR/WT-0v| RD/WT-0v

KEY ON - BL/RD-11.9v | RD/YL-11.5v | GR/WT-0v | RD/WT - 11.5v

 

GR/WT is 12v power to the blower motor.

RD/WT is ground.

 

Now, if GR/WT it showing nothing.

Yet RD/WT is showing 12v...

 

That means the relay is not grounding, and therefore not closing to complete the circuit to the blower motor.

 

For probable reasons of an anti-clutter world, Subaru has the blower motor relay ground going off into the thermostat circuit to ground there.

 

So what do I do? Chop the wire as high up as I can, take the foot and a half of wire, ground it to the frame.

 

Boom.

 

GR/WT is showing 12v.

RD/WT is showing 0.

 

Blower motor comes on.

Resistor controls current through the fan = fan speed.

And the relay now clicks and operates as it should.

 

Multimeters.

Gotta love 'em.

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Is the car A/C equipped?

 

If not, the ground for the relay should go through a few of the big connectors behind the fuse box, and then on out to the ground bolt that is on the drivers side strut tower.

 

Check that bolt.

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A/C - negative.

Not sure how long ago that was taken out.

Or rather, not installed with the twotwo swap.

 

Basically, there's more than enough "custom" electrical jobs on this GL.

Which makes jobs like this - somewhat of a challenge.

I'm slowly going through the circuitry as problems such as this one, present themselves.

 

The ground wire off the relay went into a bundle of wire and into the frame.

I was like "NOPE! This ends here."

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A/C - negative. Not sure how long ago that was taken out. Or rather, not installed with the twotwo swap. Basically, there's more than enough "custom" electrical jobs on this GL. Which makes jobs like this - somewhat of a challenge. I'm slowly going through the circuitry as problems such as this one, present themselves. The ground wire off the relay went into a bundle of wire and into the frame. I was like "NOPE! This ends here."

 

So you fixed it.........

 

By adding to the wiring cluster?

 

I preffer using the FSM and a Ohm meter to track down actual problem.......not hack in a patch.  This is a subaru not "Windows Vista"

 

J/K......glad you got it solved one way or another......at least you do understand relays and what they do/how they work.   You've got a leg up on most people.

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Subaru Windows Vista lol.

I like that.

 

I did what I could man man!

 

You're in Corvallis, you've got it a little drier. As you know.

 

With all that rain came in a month or so ago, this "no defrost problem" turned serious.

This is my daily.

 

And I did use an ohm meter. (It's a feature contained in my multimeter :P )

(Admittingly, voltage makes more sense to me than ohms)

*Pressure vs. resistance - this and that.

 

The blower motor was shot!

The motor resistor was shot!

The relay wasn't grounding!

 

Replaced 'em all and opted not to make matters worse...

Rather remedy the situation by any means necessary.

Now My T-Line rig is that much closer to being fully mountain-worthy.

 

You dig?

I know you do sir.

 

BR OUT!

 

Yeah!

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