1973 Heater thumb wheel
 

Took my girl out in the '73 lastnight for dinner, T tops off, got a bit chilly on the way home. I turned on the heat, no problem until I went to roll the thumb wheel up on the heat side to shut everything off. I can't get the orange needle (indicator) to go completely up to the top to Cold. It is driving me crazy that I am in my office at work today and can't be home figuring out what happened with the thumb wheel control. When I take it apart this weekend, should I see something obvious that has happenend?

thumbweel is connected directly to the cable control, which is connected to the temperature mix door. maybe something fell into the defroster, now blocking the mix door from moving.

Allright, can't wait to get home and take it apart and see what happened in there..(probably tomorrow morning, though).

Does the wheel feel as if it's going all the way forward.... both wheels turn the same amount of turns so check the one that is working and see how many rotations it takes, then compare to the one that isn't.

If it's not traveling the full throw, then something is stuck inside either blocking the door or it's a cable issue. The issue quite possibly may be the tang on the needle broke and it's slipped on the string, the wheel itself or the drive shaft inside the housing.

If you go to this page you'll see what I'm talking about. Click on supporting document when you get there.

1968-1976 Corvette Heater Control Rebuild

No, it's almost like it's hung up on something and almost feels "off track" or something. It does NOT roll smoothly at all. And this happened all of a sudden, has been working fine. Need to just get in there and see what's going on. I will check that link you supplied, thank you.

Thanks again for the link, I printed it out and will take it home. Can't wait to see what went wrong!!!!

I'm thinking the string came off the little wheels. Had that happen before.

Russ

That link I posted will show you how to take the thing apart and put it back together... If it's the control.... and if it is an issue, I've got plenty of extra parts to fix the original one.

Willcox

So I fixed it, basically the string came off the pulley. Grabbed the spring with needle nose pliers and shoved the pulley over and snapped the string back onto it. Crazy how the whole mechanism works. Love this forum and all the help it provides. Thanks again. Gotta go , sun is shining here in the Pacific Northwest...FINALLY.

Meant to say "string", not SPRING

:thumbs: