just got cutlass supreme and need help. :)

[AndroFlo]

Hi all.
I just found these boards as I'm looking for information on my car.
It's a 1993 Cutlass Supreme and while it's a dream car of mine (don't ask, it does need some TLC.

I've budgeted for all the repairs so spending the wrench time on this car doesn't bother me at all.
I knew the heat wasn't working when I got it, I was hoping that it would be a thermostat issue. But after a 3 minute thermostat repair it didn't fix the problem.

I'm now faced with the reality it's probably the heater core.
The car has an electronic temp control unit.

I understand now that the heater core is under the passenger side dash and doesn't require the entire dash be removed to fix. I'm hoping that's the case because when I repaired the core on my TBird it was very expensive in labor because o fthe many hours it took to tear it all apart.

The heat pushes cold air out of all vent options even when I have the temp set to around 90, and the outside temp is in the 60's. I set it to auto (i've never used an electronic temp control unit before so there's a learning curve for me).

Am I right in thinking the heater core is the trouble? And is this something that I can do myself?
I'm fairly car savvy and I'm not afraid to spend a saturady on it.
But removing the whole dash may be getting into more then I'm use to.

Has anyone else experienced this? And if so, what was the fix?

Thank you very much for any info you can provide.

~Brian

[joe12251979]

Brian,
You should be able to just pick up a book for the car, if that would be too costly, you would be right, although you may have to remove the glove box, this sometimes makes it a little easier to get to it, if not then just get under the pass dash to see it.. - Joe

[Slade901]

Well, you can verify if the coolant is circulating through the heator core by touching the inlet hose going to the heater core and touching the outlet hose going back to the main coollant hose. Do this when the engine has IDLEd for a few minutes and engine at an operating temperature.

If you are not leaking coolant at the heater core, I doubt the heater core is the problem. I would disconnect the heater core inlet and outlet hose and I would rig up something to force water to the inlet going to the heater core and see if goes out to the outlet hose to determine if it is plugged up or not.

The other problem that is mostly missed is that the heat/cold cover selector switch is not functioning. You think that the you set the heat/cold selector to heat but the heat/cold cover selector is not moving at all and so you got cold air coming.

The heat/cold cover selector switch is usually controlled by a vacuum hose on almost early 90's or late 80's vehicles. The vacuum hose that control the heat/cold cover selector switch is also connected to the cruise control vacuum hose.

If any line of those vacuum is unplugged, broken then you won't have any cruise control and the heat/cold cover selector switch is not working.

Trace the vacuum hose. First, check under the brake pedal, there is a brake pedal button switch where the brake pedal is pushing the button switch closed when the brake pedal is not applied. The button switch under the brake pedal is used to disenaged the cruise control when you apply the brake pedal. So, if that brake pedal is not pushing that button switch then the cruise control is always disengaged. Check the vacuum hose to that button switch. The button switch on the brake pedal is connected to the heat/cold cover selector switch via T-fitting and it goes to the engine bay. There is a black round or square black box that this vacuum hose connects to. It is called the cruise control servo and make sure the hoses are connected and not cracked or broken. The hoses on the cruise control servo then goes to the engine intake manifold where it gets its vacuum from.