heater controler assembly & winshield wiper operating erraticaly

The heat will not come out on the floor only on the winshield and panel modes. Could it be the contral assembly or the door in the counsel that directs the heat. The wipers operate erratically Ive heard two possible causes the windshield wiper motor and the control module which is the most likely cause.

You've got a problem! I had a'bout the same thing with my A/C, it would only vent to the floor. It all operates off vacume,pull controls from dash and check all rubber lines for any type of leaks, and follow thru into the engin compartment duing the same. There is also a vacume canester that holds vacume pressure I belive its located on the left side of the engine compartment. I dicked with mine I dont know how long, and finely gave up and bit the bullit and took it to the dealer, I still have a hard time sitting down ! Good Luck! Let me know what you come up with. DENNIS

I had the same A/C control problems on my wifes' 98. I ended up replacing one of the vacuum motors. If you pull the dash apart you can move the controls and actually see if each one is moving, I think there's five. The problem I have now is the erratic wipers, I added an extra ground, but that wasn't it. A common problem on the 88-98 fullsize was the control module on the motor. Do you guys know where it's located on the Blazer? I'd like to check that before I replace the motor.

My wipers are doing the same thing. If I mess with the connection block (grey wire connector) to the right of the motor it works fine. I haven't gotten around to actuallly fixing it but that is where the problem is for me.

I have 95 Blazer and have both these problems. I also find that the problem SEEMS to be under the hood, at the harness connector just left of the wiper motor. If wipers don't work, I leave switch set to on, pop hood and "wiggle" the connector. They kick in. I've pulled the connector apart and all the contacts look good. I cleaned them up a bit, but it hasn't fixed the problem. I wonder about the ground thing. Perhaps wiggling the connector just wiggles the whole unit enough to get a new ground? Or perhaps briefly breaks a circuit and thus "resets" something. Still a mystery to me.

On the heater controls, I've just found that they've become more and more stubborn. Sometimes the vacuum motors will gradually come around to the right settings. But they're terrible when its cold out - which is when I really need it to work!! I had some audible vacuum leak at the selector switch. Took it apart and put a little lube on the rubber disk that is the key part. Seems to have eliminated the hiss, though the system still doesn't work very well.

My wipers are doing the same thing. If I mess with the connection block (grey wire connector) to the right of the motor it works fine. I haven't gotten around to actuallly fixing it but that is where the problem is for me.


your getting very close. take the cover off of that motor (it has torx scres in it). pull out the board in their. every solder connection for that plug(that you have to wiggle to get it to work) is cracked. look at them with a magnifying glass. just take a soldering iron and heat up every connection and flow some more solder on them(i think there are 5). problem solved. very easy fix. you dont need to buy another wiper motor. ive done this several times now and its fixed it EVERY time.

Thanks Vin! When I get time I'll give it a try and let you know.

Chevy actually sent a card out telling me to go to my local dealership and have the broken solder joint and the solenoid it attaches replaced. If you have already had the repair performed (I believe it had to be at the dealership) there was a form to fill out and I got reimbursed.

The wiper control circuit was recalled. Take it to a dealer for a free fix.

The wiper control circuit was recalled. Take it to a dealer for a free fix.

how long is this recall reimbursement valid?

how long is this recall reimbursement valid?

It wasn't a recall, it was a special policy campaign. It was for trucks 7 years old or 70k miles, and it ran from Feb 03 to Feb,04.