Cliff Harris

Just for reference, the blend door motor in my '86 looks like this (plastic case removed):



The gears are in the top and the blend door lever attaches to the shaft that is sticking up on the left.

This is what it looks like from above when it's installed:

Pingman326

Ok, after I replaced the programmer I went through FSM text and the programmer passed this time . So at least it wasn't money wasted but still no heat. The test said to check door for obstruction. I removed the module mtd. Under the hood and looked In to check the door. There is a metal rod going across the opening that isn't connected to anything I pushed the door with A screw driver and it moved easily to the other side. Now I have heat ! Should that rod be connected to the door ? How do I get to it ?
Thanks

GREGGPENN

The thread linked below will guide you to correct area. (Just don't remove the heater core cover -- since you're not after that.
http://forums.corvetteforum.com/c4-t...ol-delima.html

If you look at the pic above your last post, you'll see a rod connected to the heater core motor. Using what looks like a stubby plastic (split) golf tee, that rod is attached to the arm of the motor. (It pushes into the hole in the arm).

That plastic pin may be discontinued....But it probably made by someone. You may need to post on that, find a salvage piece, or make something.

Again, the pin is split and is serated on the inside -- to grab onto that threaded rod. Place it near the end of the rod -- as shown.

Anytime the battery is disconnected, the programmer pushes the rod (using the motor) both ways. It's learning the correct extent of travel in both directions. That's done allow for variance in where you place that stubby white clip on the rod.

Still, you need to get close to the correct clamping position or you may end up w/o full heat or full A/C.

Pingman326

Thank you ! I'll get ino it tomorrow and let you guys know. The piece I saw when looking from outside the car must not be the door operator rod because the piece I saw was more like a flat piece of metal protruding across the opening. I couldn't get it to move, maybe its a brace or something. I'll take a picture and put it on the thread.

Cliff Harris

I looked into the positions of the blend door recently and took pictures. This is looking through the opening after the resistor module or fan control module is removed. The black area on the right is the opening into the HVAC ducts.

First is 60°F position. The AC evaporator is on the left. There seems to be some kind of deflectors on one side of the blend door:



90°F position. The heater core is now exposed on the left: