Heater stays on defrost only

[bigq11]

Originally Posted by bigq11

Thanks for the info. I'm about ready to give up on it. I chased the vacuum line from the manifold thru the fire wall. Then it disappears into all the foam insulation. I tried to remove some of the foam and it appears the line is headed toward the driver side of the firewall and ending up behind a large fuse box. The foam is so tuff I gave up on trying to follow it all the way to the ball.

I've ordered a new vacuum ball and finding somewhere to mount it should not be a problem. As I have been able to see where the existing line from the manifold goes thru the firewall I will run a new line in it's place to the new ball. Then I'll need to find the best place to cut the black line going to the control panel connect the new line from the new ball to this line going to the control panel. Due to the foam insulation, this will probably be under the dash. Best info I have found indicates there is check valve in the ball.

If the problem is not the control panel itself or one of the other lines going to one of the other vacuum motors, I think this should work.

Any thoughts or comments would be appreciated.

Thanks

Problem solved. Mounted the new vacuum ball under the dash, ran a new line from the intake manifold to the large connection on the ball, then cut the black line a few inches downstream from the control panel, then spliced on a new line going to the small connection on the ball.

All now works as it should.