1K SPORT

'89 convert.

I have no heat. Took it to the dealer to get looked at. They say I need a new controller/programmer. Is this the actual digital display/buttons? I know it's a stupid question. Anyway, the dealer said the part is like $250. I look in Ecklers and I see what I think is the same part for $50? Am I right? I want to make sure I buy the right part.

Thanks.

Corvette ED

The last one I installed was about $100 from Chevrolet. They are only available in rebuilt and you must give your old one back as a core. You can install it yourself in a few minutes.

Ed Ut

I bought one and installed it myself. It was about $125 and you have to return the core (old unit). Check with The Last Detail. They are the cheapest.

tommelton

There are two parts to the C68 that have problems, the "programmer" and the "controller". The controller has the buttons on the dash, and the programmer is under the dash, and has electronic connections, and a bundle of about 5-6 vacuum hoses going to it.

Depending on your problem, it could be either. Can you describe in detail what is the exact problem?

Tom Melton
82 CE
86 Z51 Coupe

1K SPORT

Thanks all for the responses.

Tom,

When I put on the heat, only cold air blows out. It never gets warm. The AC is also inconsistant. Meaning it doesn't stay at the constant temp I set it to. I hope that helps.

Thanks again,
Randy

tommelton

Randy, first, the issue of cold air. Does it blow out at your feet, or the dash vents or the defroster vents? Will the buttons on the controller switch the airflow to each of the vents, ie, feet, dash, and defroster?

Cold air can be due to at least three things. 1) engine not getting up to proper operating temp, 2) heater control valve in heater hose, and 3) Electronics (controller and programmer).

Lets start with 1). Is the engine getting up to at least 160 degrees? If not, you may never feel heat.

Now for 2). The heater control valve is located on the passenger side of the engine compartment in a heater hose that ultimately goes into the heater core. This heater control valve also has a small vacuum hose connected to it. (If you need a pic of location - let me know. ) If the heater control valve is frozen in the closed positon, you will NEVER get heat. With the car off for at least 10 minutes, check the position of the lever on the heater control valve. Now, start the car, and push the heat button, and set the temp to the highest setting. Go check the lever on the heater control valve. Did it move? If so, this should not be the problem, go on down to item 3). If if did NOT move, attempt to move the lever by hand, will it move at all? If not, you likely have found the problem, a bad/frozen heater control valve. If it did move by hand, remove the vacuum tube from the valve and see if vacuum is present in the tube. If vacuum is NOT present, go on down to item 3). If vacuum is present, then the heater control valve requires more force than the vacuum cylinder on the valve can deliver. Try working the valve back and forth to free it. If it still will not move, you can try a zip tie on it, to hold it open, and check for heat in the car. If that does the trick, you likely need to replace the valve, as the small vacuum cylinder on the valve is likely bad.

Lastly 3). I asked above if the airflow can be controlled between the 3 levels of vents. If not, it can be the controller or programmer, or any of the vacuum cylinders/cans that control the airflow doors in the HVAC system.

Respond back after testing this all out, and I can go further.

Tom Melton
82 CE
86 Z51 Coupe

1K SPORT

Thanks Tom! I'll run these test tonight. I can eliminate #1. The car does get up to Temp (about 200) when running. I'll let you know what I find tonight.

Randy

1K SPORT

OK, I can controll the flow of air using the controller. As for as test #2... I need pictures of the location of the heater control valve if you could be so kind. I looked around the passenger side of the engine compartment and don't see a lever. :confused:

I really appreciate your help so far.

Randy

tommelton

Hope that works...

-Tom

vettewally

NEED HELP with my heater control. It only works on a low setting even if put on high. What do you suggest it is.THANKS

tommelton

What year and what version of HVAC, IE, manual or electronic?

-Tom

89vettester

I have the same problem except opposite, it blows hot but not cold. After going through your tests I'm convinced that it is the heater control valve, but I'm confused. I printed out your picture and went out to my vehicle but I don't see the valve on mine. You said it was in one of the heater hoses. I see where a vacume line run into one. Do I have to cut the heater hose to get to the heater control valve, or does my model have it located somewhere else? I have an '89 with auto climate control. Thanks for any help, I have the passenger side dash torn apart trying to find the problem before I found your post. I'll wait to hear a reply before I put it all back together.

-=Jeff=-

-=Jeff=-

The 89 does nto have the heater control valve on a heater line.

My guess is assumign you have the Auto A/C it is the programemr as well or the blend door motor.. which is located on the Passenger side