Picked up a 76 century and when set to vent it still blowers out the lowers and not the vents. Is this a manual control, vacuum or electrical? Where should I start looking to correct this? Also, the compressor was removed and none of the a/c settings blow. Is that because the compressor is gone and it is needed to complete an electrical loop? Are these two things probably related? Thanks for any help!
If its not blowing out of the dash, that's a vacuum issue. First thing is to check that you actually have vacuum going to the heater controls. The switch on the dash just directs vacuum to the diaphragms. If you have a hand held vacuum pump, you can check the diaphragms individually. Apply vacuum and see if they operate and don't bleed off. That's dependent though on if you can reach them. Chances are if you have good vacuum going in and the switch is operating properly, you have a bad diaphragm somewhere. I think there are 3. You can try taking off the passenger side kick panel and seeing if there's one under there like the 70-72 cars. That one should have 2 vacuum lines going to it. Pinch off those lines and see of it blows out of the vents. If it does, you just found your bad diaphragm.
I'm wondering if the vac line isn't off altogether? When I picked up my '69 I only had air from the heater outlets. Found the vac line was off the canister. Refitted it and it's worked ever since.
