No Heat 1996 Bonneville

[ve6aq]

1996 Bonneville – Winter time – No Heat

This winter was a winter of car heater problems. Well they don’t call it a heater these days – they call it an Electronic Climate Control system.

It all started when I was driving home from St. Albert one cold day earlier this winter. All of a sudden it was quiet in the car as the heater fan just stopped blowing air. I fiddle with all the temperature controls but no go. It is a bit of a struggle to take the bride to the Opera in a vehicle with no heat. I did not have the courage to say, ‘Just warm up some bricks and take them along to keep warm’ Anyway after looking through the service manual I thought I could find my way to the fan motor. Not that easy bud! I had to remove two layers of fuse panels and cowlings under the hood before I got to the controller that controls the fan. Well I found the problem was a burned up connector. No problem, I said, and headed off to GM with the burned three pin connector in hand. ‘No problem sir, we can have that for you this afternoon’. $72.00 please! So I was back in the afternoon with my sample. The part they brought in did no even look close to the part I wanted. No thanks I said and headed home and soldered the connection together. I put the layers of stuff back and the fan worked great. I thought that the heater problem was solved but wait!

These Electronic Climate Control systems use a microprocessor to control the temperature, fan speed and direction of the airflow. Well the fan was now running but the temperature of the air coming out was sometimes cold, sometimes lukewarm and sometimes hot. Then if you fiddle with the controls you finally might get heat. About the time you get heat you are at your destination. I left it for a few weeks figuring it might automatically cure itself – aren’t those microprocessors suppose to do that?

Well it did not get any better so I dug into the service manual again and onto the Internet to search out what to do next. The experts said just take out the glove box and you will be able to see the controllers and all the stuff for the heater. Wrong. All one could see was two one inch holes to peek through to see what was going on. From poking through those holes I could see that the problem was that the motor gearbox that was turning the lever on the air flapper was defective. The gears must have been stripped as the shaft was turning freely and a working worm drive just does not do that. That flapper is designed to direct air through the heater core or through the air conditioning core depending on temperature of the air you want in the car.

So now I had to go under the dash to pull out the vacuum/electrical controller so that I could get my hand in there to pull out the gearbox. Well picture me lying on my back with one foot out the door, holding a light with one hand and trying to remove one visible screw and one semi visible screw with a little 7mm wrench. After one hour the two screws were out. Now to remove the five vacuum lines molded into a plug that had not been touched for 17 years. Sometime these lines collapse onto themselves because of heat. I finally pried that vacuum connector off without destroying it and it checked out OK. Then there was the electrical connector assembly from under the dash, which one needed two hands to get out. Try holding the light in your teeth, your body in the right position and two hands trying to work in a space limited to one hand to get the connector apart. So now the vacuum/electrical controller was loose but there was one electrical connector to take off at the top.

Get this – the instructions said to move the controller out of the way so that you could get your right hand up through the space to disconnect the electrical connector at the top. Well I could get one hand up there and just touch the connector but those connectors are tight and you need two hands to get them apart and sometimes a third hand holding a screw driver to pry things apart. There was no way I was going to get that top connector off.

Plan B. Well I got off of the floor, sat on the seat and looked through the glove box entry way again. I decided to cut a 2 inch X 8 inch long notch out of the metal plate blocking the access to the heart of the controls. So out came the single blade hacksaw. It did not take too long to cut it. (Deciding to do it took longer). Then I figured that I was not going to take anymore stuff apart as I still had not removed the defective module and there were a few hidden bolts to get out of there. I decided to put a manual control to pull and push the air control flapper valve. I got a choke cable. A choke cable is what they used to use to control the choke on carburetors on cars in the old days but they still sell them at the automotive shop for $10.00 or so. I connected it to the air flapper valve, ran the cable behind the glove box and under the dash to a control knob installed semi hidden in the passenger compartment.

Now I have heat in the winter and cold air in the summer merely by pushing or pulling the choke knob. The other automatic controls still work. I am now recovering from the stiffness from all the unorthodox positions I had to put by body in.

Denis
February 9, 2014

[impala67]

wow. respect to your suffer. i hope i dont have to do same thing in 5 years...mine is -91

[Sirius]

When I did mine, many moons ago, I took the passenger seat out. That made a big difference. I'm relatively small and I hated trying to get under the dash with the seat in place - can't imagine a large guy trying to manuever around under there. I'm also fairly old so contortioning like that doesn't do me any favors. If you ever decide to get in there and make it right, look for the Tech article relating to the ECC problem. There are a couple links in the article that may be of help. Getting the offending connector you mentioned OFF is one thing, getting it back on is quite another.

[MattStrike]

I did that last summer on my '93. If you take out the passenger seat it makes it a lot easier on your back.

But it's definitely not a winter time job - that choke cable is the best way to handle it until the weather breaks.