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Weird Heating Issue

Featured Replies

I'm having an interesting heating/AC Issue on my '88 GL Wagon. Heat blows Hot, and AC Blows Cold but I get almost no actual blowing air out of the vents.

 

I thought maybe the vents aren't changing modes. So I first checked the vacuum line under the hood, and checked the line all the way to the mode selector. All good.. Then I then checked the ducting, Mostly the defroster, and switched modes. The doors open and close. Still getting almost no air blowing out of my vents.

 

One thing i noticed though... when i switch to defroster, It blows, not much but it does. I get cold air blowing through my dash.

 

Anyway, My Blower works! I checked that, I even rebuilt it, and tested. When its free flowing, it blows pretty steady and well.

 

So my question is i guess.. anyone have any suggestions where i should check next? Maybe my exterior air intake is clogged up? and thats why its not blowing much when i re-install the blower? where is that ducting and how do i get to it?

 

 

-Justin

pull the blower motor out and check for debris/insulation up through/in the vent lines.

  • Author

well i pulled the blower out, didn't find any debris other than a tiny piece of tape. i felt in through to the left (towards the core) and up to where the air comes into the blower, didnt find anything. where does that intake come from? maybe its blocked? maybe the fender?

 

 

-Justin

  • Author

interesting..

 

So i was driving home and i heard a duct door either slam open or slam shut. didnt do much for the air flow. didnt seem like the selection changed. (i was in heat mode) is this an indication of something bad?

 

 

-Justin

  • Author

Does anyone know how the ducting is layed out on the '88 GL's? Is there a Door that closes/Opens before the blower for both the Circulating and external air? also, is there a door just after the core?

 

 

I'm trying to figure out what exactly the problem might be without dismantling the entire dash. I halfway did it and didnt seem to be something "Fun"

 

Edit: I keep hearing something slam under the dash.

 

 

 

-Justin

Edited by crazyman03

Remembered this thread while I was out in the garage today, so I looked over the units I have here out of an '86 Sedan and an '88 XT6.

 

They were identical except for the Xt6 has electric servos, vs vacuum on the '86.

 

Only doors found are cabin/outside air, defrost/vents/floor.

 

Nothing found that would restrict airflow thru the system.

 

Outside air intake for the blower motor is under the wiper cowl on the passenger side, just off to the side of the area that the removable cowl grille meets the stationary part. Basically directly above the blower motor itself.

  • Author

Hmm.. Thanks tom!

 

I will try checking that. It's been cold here lately i cant get out and look/fix it; cant get it into the in-law's garage and freeze my butt off! its a catch all the way around! :rolleyes:

 

I Spoke with Breeke a couple days ago in the chat and mentioned double checking voltage for the blower.. It blows great but double checking +12.

 

Thanks!

 

 

-Justin

The resistor block gives the blower speeds, depending on switch settings. You can loose one or two speeds due to bad resistor block, but still should have airflow.

 

Really sounds like you have something in the system blocking the airflow. Maybe from a PO's forray into the system to repair some other problem.

 

Only items in there that could block flow are the AC coil and heater core themselves., and or debris getting trapped against them.

  • Author
The resistor block gives the blower speeds, depending on switch settings. You can loose one or two speeds due to bad resistor block, but still should have airflow.

 

Yea, i only have speeds 3 and 4. Well More 4. I don't mind having it on hi all the time, if i get too hot I'll turn the thermostat down. Just need to get to the point where its making me warm :mad:.

 

I was out there tinkering with it a bit ago. Not much I can do at the moment since I'm at work but the airflow doesn't seem like its in "default" mode or that its sending air to all 3 modes... Couldn't see much into the cowel. Seems like much of a project to be doing at work.. :-/

 

Thanks for input! Least this gives me a bit of a start.

 

 

-Justin

  • 2 weeks later...
  • Author

Well, i *finally* got to take apart my car to figure out my heating gremilins. I checked the air intake from the outside and found.. nothing clogging it up. i took apart my dash completly (not a fun chore i might add) figured out that all my doors are opening/shutting when they are supposed to. and still found no clogging.

 

the only thing that i was able to find was the driver "vent" was stuck open to the outside. This would explain the cold air that i feel coming through the dash vents when i have everything off. i found that the cable was broken. and since i don't use it all too often i didn't feel bad about permanently closing the outside vent.

 

I'm still not getting much as far as airflow goes. I get +12 at the motor! I'm pretty confident that the blower is working properly.

 

Am i just being senile?

 

 

-Justin

you are not senile I too have the same symptoms and everything checks out fine.

  • 2 weeks later...
  • Author

ok, so apparently I /am/ ceanile. I grabbed a *new* blower from the junk yard and put it in, blows great! and now I'm not freezing my arse! (those -15 degree mornings we've had have been killing me!)

 

 

-Justin

Good to see you fixed it! Heat is fantastic in the morning, especially with remote start! It's now been weeks since I have gotten into a cold car :)

I was thinking wrong rotation on either the blower motor or the squirrel cage, but didn't think it was possible on Subarus so I didn't say it. Do know it's possible on "other" makes/models. Learned something....

When you rebuilt it you could have reversed the wires inside to cause the motor to turn backwards. I know it's possible, I did it twice! :lol:

  • Author

i did check for wrong rotation but it was going the right direction. suction from the inside blowing outside. i was getting *some* air through the vents but it took forrreeeevvveeerrrr to warm up. for example. a couple weeks ago i drove it down to pueblo which is around 160 miles away. i had a t-shirt, sweater, hoodie AND Carheart jacket on and i was still cold! much happier now!

 

 

i still have other random gremilin issues but they dont require taking the flippin' dash apart again!. i also picked up a blower regulator at the junk yard, might put that in too and see if it works

 

 

-Justin

Glad you got it figured out, being cold sucks rump roast.

 

I just got my heat back to yum yum hot! yay yay!!!!!!

 

 

I know the feeling, snowboarding all day, and then getting into a cold car for a cold 2 hr drive home....BRRRRRRR

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