'68 A/C Trouble Shooting ?'s

[bchampion]

So, it seems that no matter what setting I have the a/c controls in, the air blows mainly out of the floor ducts. Very little comes out of the dash vents and I can get nothing to blow out of the defroster ducts. Any ideas?

Thanks,

 

[Tim65GT]

I don't know how similiar your 68 controls are, but my guess is one or more of the cable slipped off at the AC air box lever end or at the control end.

Here are some pics: ( the unit is a Vintage air, but you get the point.

AC Air box flapper control cever

Control lever assembly with cables

 

[65ShelbyClone]

My '68's HVAC controls work pretty well since I hooked them up to manifold vacuum....

 

[bchampion]

Are you not using the vac canister?

 

[rbohm]

So, it seems that no matter what setting I have the a/c controls in, the air blows mainly out of the floor ducts. Very little comes out of the dash vents and I can get nothing to blow out of the defroster ducts. Any ideas?

Thanks,

start by checking the vacuum motors that control the doors in the system for proper operation. a vacuum pump would work real nice here.

next check all the vacuum lines associated with the system for leaks or cracking.

after that check the switch itself for proper operation.

make sure the vacuum can is hooked up, and make sure you have a good vacuum source.