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Heater Assembly how-to


bgd73
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  • I took apart the blower unit side of things, decided to clean up the bunged up heater motor - took the motor all part, regreased, looked things over it was quite dirty, now spotless and greased. Brushes do not have much time left. The motor is much less strain now, however,the heater resistor stays cool for all 1-2-3-4 settings.
  • Upon putting back together and sealed, I heard something like clumps of dust go flying towards heater core unit (behind radio) and now with heater engine full speed ahead there is hardly an air flow to match.

Where is air going? I checked surface of heater core (do not ask me how I pretzeled upside down and squeezed my head under the dash to get a look) and I cleaned that out of small things, overall looked good fins are sharp and open. Is there an easy way to find a major clog elsewhere in the heater core side? I verified fan is full speed by taking the duct between heater motor and heater core unit off and it is indeed blasting air in that direction. Put duct back on and its hardly pumping air with motor obviously revved up to where it is supposed to be. The sound of debris going toeards heater core was last hint I bunged it up somehow.

 

Below is photo worth showing- it is a rusty holder of the heater resistor block that stay on the inside of unit. I painted this one and called it good. The rusty metal could be a resistor block killer

 

hrestirholder20yrzn4.jpg

 

EDIT: I do have a chiltons manual that shows externally the heater system parts, but not the inside. The FSM scored here does not have it in it.

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[jumping into the middle]?

 

You are saying that the blower runs, but no air moves out any vent (heater / floor center defroster)?

 

The shutters that select where the heat goes can't block all flow, only choose where it goes.

 

There are 2 shutters that direct air through or around the heater core. It seems possible [not sure how likely this is] that if the linkages were messed up they could block the air.

 

What are the chances of mice / etc. making a nest in the ductwork? I had them build one in the blower years ago. Found the *whole* system filled with nests in one of my parts cars.

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[jumping into the middle]?

 

You are saying that the blower runs, but no air moves out any vent (heater / floor center defroster)?

 

The shutters that select where the heat goes can't block all flow, only choose where it goes.

 

There are 2 shutters that direct air through or around the heater core. It seems possible [not sure how likely this is] that if the linkages were messed up they could block the air.

 

What are the chances of mice / etc. making a nest in the ductwork? I had them build one in the blower years ago. Found the *whole* system filled with nests in one of my parts cars.

 

That is the conclusion I came to about the air getting guided- it is indeed functioning, every setting. I bypassed heater core simply by putting the air temp to cold- still slow. I verified that outside air was coming in for the blower-it is full speed ahead without duct on. why it is disappearing while making all the noise that it is full speed is bizarre. .The only hint I have is the sound of debris flying towards heater core, and then suddenly bad flows. Everything works. I did find a nest under the windshield wipers where vents are, and threw it all out as one clump, never got sucked in, heater worked great before i found that.

 

Another thought is that I had the blower motor apart to grease and clean, and balanced the plastic fins and it is now balanced. I am wondering if while under the pressure of heater box the noise is there but the actual "umph" to get the job done isn't happening. Makes the same noise as before, but now balanced- it is hard to tell.Out of the heater box it really sends the air flying- with same exact noise on high, as in the heater box. I am stumped. Will try another heater resistor hack job I have around here somewhere to reassure myself the motor is getting full power- I think it may be tricking me.:rolleyes:

It is hanging onto resistor block now however.. I must have done something right :)

 

Edit: what does pass though for heat is quite warm, the warmest I have ever felt the heat. Will try blowing out the heater core with high pressure air needle as well.

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ok here is summary, now need an experts guess

 

  • heater resistor block back to all oem
  • heater motor greased and cleaned, back together balanced (higher powered and quieter than ever)
  • verified outside duct function at heater motor with glove box out, car running and switched heat on and off, valve moved, and even moved it by hand as well to check for full movement
  • to the left of heater core unit, verified the valve actuation moved there and routes changed with heat on high (it all functions)
  • visibly inspected top of heater core- clean and sharp

A symptom of something wrong was just after pressing any given route like "bilev" there is a blast of expected warm air, then something of a valve is doing something to slow it to the crawl of air I am trying to do away with.

Is there some kind of alignment to verify?

Whatever it is , when I fix it, I will post what it was. My other 87 did this for a short time, and came back with a thud at what sounded like behind the dash clock and it was full speed ahead again (there isn't even a valve there :confused: ). Similarly on this 87, I can hear a whole lot of air at center of dashboard and cannot find any leak inside the car from the area of noise...

Is there another route besides the channels given at controls? back outside somehow? The heater motor is indeed full speed ahead powerfully. #1 speed is nearly useless all while engine runs and I can still hear it.

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I guess I am gong to have to tear the heater core box down myself.. will get photos. the little plastic lines after 20 years aren't even petrified. Having no a/c made this problem seem smaller, by taking out the whole box. I can smell amouse and I am sneezing and there is no recycle at all going back though the defrost vent... something is in there. Anyone else guess before I dig into this shortly? four of my own posts has left me on my own again... :confused:

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bgd-

I know nothing about heater cores and hope never to have to learn (from everything I've ever read about 'em). So here's my probably useless idea: Do you have a more-powerful-than-a-hairdryer blower? Like a leaf blower or shop vac that you can run as a blower? If yes, then try blasting INTO the vents (i.e. try to reverse the usual air flow pattern) and see if you get lucky and dislodge whatever mouse nest or piece of junk is plugging the works up. Probably nuts, but I thought I'd throw the idea your way....;)

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bgd-

I know nothing about heater cores and hope never to have to learn (from everything I've ever read about 'em). So here's my probably useless idea: Do you have a more-powerful-than-a-hairdryer blower? Like a leaf blower or shop vac that you can run as a blower? If yes, then try blasting INTO the vents (i.e. try to reverse the usual air flow pattern) and see if you get lucky and dislodge whatever mouse nest or piece of junk is plugging the works up. Probably nuts, but I thought I'd throw the idea your way....;)

 

 

Thank you, Excellent idea.:)

 

I really have a nuts idea though.. I cleaned everything top to bottom, I even situated myself to actually see the light of day through defrost vents from the bottom side of heater core unit.. the duct off the engine is as powerful (quite powerful) as I cleaned it up to be, nearly buzz free. With duct on, engine same power, airflow simply DIES with routes wide open and verified. It is quite fixed, and must compliment it, as this cars 20 years has been north climate all the way to alaska its whole life- a heater motor with alot of miles to be as quiet as it is....impressive.

here is the strange conclusion I learned from my other 87... something "atmospheric" is happening. From top to bottom back over through the heater core (which really is clean, I verified again today).all ducts open, I visibly watched each link as I went through the buttons to see them change- and air is climbing out appropriately in correct places. My other 87, just as mysterious after taking motor off and putting back on, "banged" back to life and really started pumping air, this one is in that stage of strangeness now and am expecting a thud. There has always been a half recycle type move back though defrost vents when heat is on, that is not happening yet... when it does, I will sure as heck know it, it returns with a thud, all while not changing routes or opening valves and increasin air flow dramatically. I'll just keep running it on high in other words.. would love to decipher that someday. Some kind of vacuum or something, I really have no idea.
:confused:

 

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after finding 2 other threads in relation to an 87 wagon and strange heat flow probs- while every part proves good-

I am dismantling what I can. I have a "best guess" the heater motor is having zero recycle and it appears to be missing- restricting flow. It is trying to pump up the interior like a car tire and that simply cannot happen on any vehicle- I must have tricked a damper of some kind closed and would like to know where it is exactly (there would be no valve for this to control manually on the 87). This same car when first bought with a clogged vent on driver side was really throwing the air around on a slow dirty motor- with an obvious air flow getting sucked in at defrost vents when heat is on, and sucking through another place when defrost was on, that is not happening now. Inside the heater core box is the prob I am certain... even with open ducts it must be missing a recycle (partial balance of outside air and interior air). Anyone here take one apart?

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Not possible to pressurize the car, it's vented through the tailgate. Besides, that means that if you open a window a hair or open the door, it would start blowing again.

If the motor sounds like it's spinning faster than usual, check the air inlet, and make sure it's clear. These little squirrel cage blowers won't produce pressure, but will draw a slight vacuum.

Also, see if it does the same thing in both fresh air and recirculate settings.

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I can't remember what the blower moter assembly looks like at the moment(too much wine:drunk: ) but is it possible that you put the fan on backwards, or actually upside down? It probably only goes on one way.

that or the debris you heard was dislodged by the increased airflow and is no clogging the duct.

I like the idea of using the leaf blower, Maybe you can remove the blower motor and blow through there.

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I looked at the blower fan closely... it had a problem. OEM wasn't exactly maximizing it either for the cubic feet of a wagon, even when fan is in perfect condition.. I also noted how quiet it stayed even out of balance and the bad condition some blades were, so at no risk, I started snipping away at it to gain a longer less passive leading edge to dig at air at the top to set a decent pace. Sure enough it worked. Problem no more. I over doubled the leading edge "dig". Air is flowing again.:)

 

blowerfan87glhg5.jpg

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So you hacked the cage up and now it blows air fine?

 

Yep.

My other 87 was just as frustrating- it was the darn blower motor the whole time (I drove it for 8 years.. not even double guessing oem..) at 40 degrees it pumps more. That is a bit backwards for my locale, the colder it gets the less it pumped. something was hell bent atmospherically to stay upside down. The hot heater core and real cold weather creating a clash(?) is my best guess. The sedan I had was way different on same motor and fan no doubt due to less cubic feet of interior- it worked perfect in smaller interior. As it sits now, the heater fan is cold for my install after snipping, and it took 30 seconds or more to really start pumping, if it is moving the cold now, as hot air is easier to move if not clashing the source, it should really get it going at all temps outside. :)

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Still searching for a how-to. Had a haynes without the heater info for loyale and GL, sure enough the chilton's does the same thing.Both books were for the loyale/gl/dl. and the chiltons even has svx, xt, and justy with a bit of legacy- No Loyale heater info (what a ripoff)..

Does anyone have a book title or isbn# for the info that really does contain thoroughly the "heater core ASSY" for 1987 GL? loyale, dl?

it is turning out to be quite a complex compilation of doodads I don't just want to tackle with vise grips and duct tape... :banghead:

deriving conclusions from other subaru digrams, is proving to be impossible. They are all dramatically different.

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