rocketraider

Tempmatic in the Custom Cruiser wagon has gone about 5 years now without a hiccup- until this week, when the weather got nice and hit 70 degrees.

It is now convinced that it should lock into max heat. With it set at 65 degrees, it is blowing 120 degree air at the vents. Once in a while, it will cycle to full cold and then immediately back to full hot. You can hear the doors switching when it does this, so it's working, it has just lost its little Tempmatic mind.

I have a pretty good idea what's wrong, but I am out of vacuum checking relay valves and I cannot get to the dealer to pick one up. When I bought the car, the previous owner had actually plumbed a vent line into the vacuum source- apparently this one had been notorious for doing the full hot thing. If it locked in full hot, open the glovebox, pull the golf tee out of the vent line and allow it to reset itself. But me being me decided that wasn't necessary. I sure wish it was still there


The last time it went wacky, it was 90 degrees and I had the A/C on. I noticed it was getting hot in the car and thought oh hello, the compressor has quit. Then I looked at the thermometer and it showed 120 degrees. I knew then I had a Tempmatic problem.

It locked in full cold on a 22 degree morning years ago.

The vacuum checking relay valve was the cause every time.

Something about outside temperature changes it doesn't like...

Lady72nRob71

What year is your CC?

rocketraider

It's an 83, Rob. It's done this mess off and on thruout the years and takes half an hour or so to fix. The biggest thing that bugs me this time is I can't get the part to fix it right now. I'd have to go thru the Chevy dealer and they are closed on Saturdays and when I get off work.

The Buick-Pontiac dealer where I used to get my parts (and who was open Saturday mornings) was forced to close by GM after being in business since 1924. Part of that "one GM dealer per sales territory" nonsense they came up with a couple years ago. They made them relinquish their franchises to the Chevy dealer, and made the Chevy-Buick-Pontiac dealer 30 miles east relinquish their B-P franchises to the Chevy dealer in this town.

And GM wonders why people have left them for other makes in droves. Their management is stupid- completely stupid. I don't WANT to have to drive 40 miles to get a car serviced, and I am not GOING to drive 40 miles for it.

I got all ideas I'll be putting the vacuum vent line back in it this afternoon. Shoulda left it there to start.

joe_padavano

Sounds like you've learned the same thing as Toyota about replacing a simple cable with electronics...

I was going to swap my 84 over to Tempmatic, but I'm having second thoughts now.

Yellowstatue

Have you tried electro-shock treatments....it works on me

rocketraider

I have found that a well-placed hammer blow works wonders on these vacuum relays. Seeing a bad one shattered on the floor makes me feel better anyway...

Joe, if a car did not come with ATC, I think you're better off not to add it. Tempmatics aren't as bad as Comfortrons, but they can sure have their moments.

Electro-shock for Tempmatics, exorcisms for Comfortrons!

Oldsguy

Got a similar problem on my d/d '99 LeSabre. The air will not circulate to the dash vents, only the windshield vents and the floor vents. Something about a vacuum operated control box which is behind the glove box. There is either a leaky port or a loose vacuum line supposedly. The design of the dash on that car requires an almost complete dash removal to get to the sill thing, can't just pull out the glove box. Bummer.

joe_padavano

This is definitely a vacuum leak. The system is designed to default to defrost and floor if vacuum is lost.

70 cutlass s

I would look under the hood first. The vacuum line in these cars are plastic. Its on the back side of the engine. Sometimes the line gets kinked or bent.