Hvac controls

[7TCatvert 24]

So, my Hvac switch is not working right the blower works fine it is stuck on defrost. Which I guess, I read, is the default.

 

So steps to take to diagnosis.

 

1 test the vacuum can and then check lines are hooked up....

 

Then?

[danno 128]

yes, it sounds like a vacuum leak.  You can disconnect the vacuum line from the reservoir to the inside. Blow on this line, and you should not be able to do it continuously.  You probably have a hose disconnected. 

[7TCatvert 24]

I found the hose schematic online and this weekend will be able to track each hose to the proper place and make sure one by one...also it is an ac car but ac is discontected I wonder if that would effect it...

[barnett468 418]

What is an hvac switch?

[7TCatvert 24]

Heat ac vent controls on dash

[barnett468 418]

ok xlnt

 

pull hoses off vacuum cans under dash and check them with the vacuum gauge

 

pull hoses off the valve/switch on the front of the heater box with the gauge and check vacuum .  . there is an arm that is operated y either the heat or the ac position that is cable operated and opens and closes the switch it should show vacuum in one position but not the other . . f it shws vacuum in both psitions, the arm may need adjusting or the piston in the vlve may be stuck or the vave may e ad which they often are . . your sytem will no work if it, or ny other valve is bad . . vintage auto air in florida has that valve.

 

there is a small plastic arm on the top vent tht breaks so check that.

 

this is only accessibe if the dash is off . . i would tke it off anyway

 

if the vacuum can on the firewall eaks, you can sometimes fix them with JB Quick.

 

your ac cmpressor has nothing to do with the vacuum system.

 

good luck