Heater blues

Mekanic · #1 10-31-2002, 10:05 AM

I have a 1990 Buick LeSabre with the 3.8L engine and an automatic heating and air conditioning system. All electrcal, thermostat and heater hoses etc are working. There is no interior heat (the blower motor does not run) when it is sitting outside. When I bring the car into the garage for about 15 minutes, the heating system works fine. (ie lots of heat and blower speed)
I suspect that the outside temperature sensor is defective? Any other solutions you can recommend would be helpful, thanks.

Racincc85 · #2 11-14-2002, 07:50 PM

I've got the same car. How cold is it outside when the heater doesn't work?

Shortbus · #3 12-18-2002, 06:58 PM

If it is not the ambient o/s temp sensor you probably have a bad hvac programmer, or a delayed blower control module. We probably have replace the programmer the most though. I don't know of any way to check the module though.

Mekanic · #4 12-19-2002, 07:24 PM

thanks for the help. I bypassed the O/S temp. sensor but we still had the problem. I found a defective blower motor connector, repaired it and it seems to be working fine now. Any experience with the HVAC programmer? I removed it to replace the AC evaporator, but now the programmer won't move the door to change the air flow to the dash ducts, floor ducts etc. it stays in one position only. Thanks

Shortbus · #5 12-20-2002, 10:29 AM

Sorry I don't have any good advice for you there. Since you said you had it out I would double check the linkage arm to make sure it is not bound up and would take it back out and see if it works when not connected to the door. The only other thing I can think of is check for power at the connectors. If it still don't work 12 years is pretty good to get out of one of these.

Mekanic · #6 12-20-2002, 11:43 AM

thanks for the info on the HVAC programmer. What do you know about lighted steering wheel controls? I have a 2001 Buick LeSabre, and the lights behind the radio volume switch and the heater temp. switch are both burnt out. The other steering wheel switches lights are working fine.
Do you know how to remove the switches to get at the bulbs? (if they use bulbs) Thanks

Shortbus · #7 12-20-2002, 12:19 PM

No listing for just the bulbs but the switch is not to expensive.
It depends on what options your car has. If you want give me your 17 digit vin code and I can tell you exactly how much. Ballpark price is about 20.00 for the Right Hand Volume and Temp cntrl switch. As far as getting the switch's out, my diagram shows that they just pop out and are not held in by anything. Also the Volume and Temp switch are serviced as one piece.

Mekanic · #8 12-21-2002, 09:59 AM

thanks for the info, I will try to pop out the switches and see what they use for bulbs.
Thanks

bowtiebandit · #9 02-02-2003, 01:16 AM

This may help..
CLIMATE CONTROL BLOWS COLD AIR DURING EXTENDED IDLE #90-I-4 - (02/02/1990)
MODELS AFFECTED: 1989-1990 ELECTRA AND LESABRE MODELS WITH C68 CLIMATE CONTROL AIR CONDITIONING

A condition may occur on some 1989 and 1990 Electra or LeSabre models with C68 air conditioning where during extended idle, the ambient sensor will be influenced by radiant heat from the radiator.

If this condition occurs, the exterior temperature display on the A/C control head will show a much higher reading than true ambient temperature. The false higher reading may cause the system to blow cold air cooling the vehicle interior below the requested temperature.

IMPORTANT: This condition will be apparent ONLY on extended idles generally longer than three (3) minutes. The system will return to nomal operation again with the vehicle in motion.

To correct this condition the ambient temperature sensor should be relocated to the center support bar using the following procedure:

1. Remove radiator grille.

2. Remove ambient sensor and bracket.

3. Remove ambient sensor from bracket and discard bracket.

4. Remove "J" clip from ambient sensor attaching hole.

5. Remove screw through the retaining tab on the P/S cooler line located on the center support.

6. Attach the ambient sensor and the P/S cooler line bracket to the center support using the original bracket attaching screw (see Figure for location and indexing of sensor).

7. Route sensor wire along center support.

bowtiebandit · #10 02-02-2003, 01:18 AM

IN-CAR SENSOR HOSE CAUSING LACK OF TEMPERATURE CONTROL #90-1-124 - (05/10/1990)
VEHICLES AFFECTED: 1989 and 1990 BUICK C/H MODELS

CONDITION

An inoperative or partially inoperative in-car sensor system has been found to be a possible cause of lack of temperature control and/or temperature overshoot.

The following should be checked if this condition is encountered on the subject vehicles.

CORRECTION

1. Assure the in-car sensor hose is properly connected at both the aspirator and in-car sensor ends. Assure there are no kinks in the hose.

2. Assure the aspirator is firmly seated in the HVAC case and that none of the four attaching legs are broken or the seal is damaged.

3. Assure the in-car sensor and the foam seal are properly seated. There must be no air leakage past the foam seal.

4. The instrument panel trim plate seal must be against the edge of the trim plate and provide a good seal between the trim plate and the instrument panel carrier. This seal assures the sensor gets an accurate air temperature sample from the passenger compartment. If this seal is mispositioned, air will be drawn from behind the instrument panel indicating an incorrect interior temperature to the sensor.

Mekanic · #11 02-02-2003, 08:33 AM

thanks for the info on the ambient sensors, I will check those out.

1989Buickguy · #12 12-19-2003, 01:17 PM

Where is the blower control module located for a 89 LeSabre?

joshey · #13 12-20-2003, 09:44 PM

in the 89 buick does it have electronic unit or manuial and also it might be the same thing in cars that old they have an odd resister for the blower(on the manual ones at least) that is mounted on the under hood blower box

1989Buickguy · #14 12-20-2003, 10:20 PM

It has the electronic control. If I whack the dash, I can get it to work on high, but it doesn't work on low. It's weird. Sometimes it won't kick on until I've been driving for a while. Also the air is lukewarm most of the time. Would a bad T-stat affect operation?

Michael Kammer · #15 11-07-2004, 07:32 PM

What originally started out as a failure for the HVAC to switch air from the Defrost to the interior has gotten worse.

I have checked all fuses and they are fine.
There is no Relay activity.
Currently the HVAC will not come on at all. No blower moter is heard.

2 weeks ago we were getting blower moter and heated air out of the Defroster slots, now that is gone.

Ideas?

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