ive got an 88 thats n/a, and the heat doesnt work worth a crap. i have a few ideas as to why but wanted to bounce what i had off everyone and see if they had any other ideas. no perticular order.

1.someone put in a 160 t-stat
2. t-stat stuck open
3. clogged heater core
4. bad heater controls

I'm not sure whats up with the heater controls. the only one that seems to work properly is the defrost. if i push any other button the light lights up until i let go of it at which point it blows cold. the car is misssing some interior dash pieces so i can watch the door in the vent in the dash open and close and you can hear the changes being made no matter what button is pushed. i will probably put a new t-stat in just because i can, and while im at it i will see about flushing the heater core. but what are the chances the heater control is the problem?

 

Logicons (heater controls) are a common failure due to cold solder joints. Normally resoldering them fixes the issue. The air mix motor is another one. Testing procedures in the FSM.

 

really? so you're thinking heater control over anything else. hmm. will look into that. may need to find someone on here to look at it and work on it cause i dont know these things, and i cant solder to save my life. thanks.

 

You can also likely find a used replacement for very little. When you have a few more posts, you may use the classifieds section of the forum to track one down.

If you've got buttons that don't work on the logicon, it's not a stretch to think the hot/cold adjustment may not be working either. Normally when you slide the lever towards the hot end of the range, you can hear the valve open to allow water through the core. It's been a little while since I've been under the dash, but I think the valve is visible with the cover removed (the one covering the heater core). You might try moving the lever on the logicon, while watching the valve to see if it's opening.

 

no the heat adjuster doesnt work. when it blows it blows at 1 temp no matter where the slider is. the only time the temp changes is when you switch from defrost and the light above what ever button you pushed goes out, then it blows ambient temp air.