Recirc Door and probably other blend door issues

[96-2D-Hoe]

I've noticed my recirc door opening and closing while the AC is on, and also while it/everything is off.

So there's something up there if anyone knows how I should check that out please?



And also are there any vacuum hoses / controls in the blend doors?

Yesterday I switched the vent direction knob from the center vents (far left) to the windshield (far right) and the idle went all over the place indicating a vacuum leak somewhere.

Any ideas with what/where to start here?

Thanks.

 

[east302]

Man, you haven’t shot that thing yet? Lol

There are no vacuum actuators on the dampers, it’s all electric and powered through the control panel.

Each actuator has a silver notched dial on it that serves as a position indicator. They should rotate smoothly, roughly between 10 and 2 o’clock. Usually when they go bad, they make a ratcheting sound and oscillate slightly back and forth.

I’ve never changed my recirc actuator, but it’s buried up there. Ideally, you’d pull the connector on it and see what your voltage reading looks like - if it’s consistent or fluctuating or if you have voltage when you shouldn’t. If it’s opening and closing irregardless of the panel setting (and you’re getting a weird idle fluctuation) then I’d suspect something with the control panel.

If I was going to throw a part at it, it would be a junkyard control panel.

Edit: the only vacuum you’ll have is the line from the PCV fitting over to the heater valve solenoid on the firewall near the accumulator. And another from that solenoid to the plastic valve on the heater lines. The solenoid is energized when the temp dial is set to the “max” detent to allow engine vacuum to close the valve and improve a/c performance.

Might be worth checking to see if the lines are busted. Also, pull the connector from the solenoid and see if you have voltage there when the panel is not set to max. You shouldn’t. Could be your panel energizing that solenoid and then leaking through a busted line.

 

[96-2D-Hoe]

Thanks for the reply and suggestions Scott.

I just drove it again and moving the vent dial definitely makes the idle screw around. I just replaced the vacuum hose and the heater valve but I guess the hose could have fallen off. If not that's just weird why the idle changes if there's no vacuum control.

I don't hear any ratcheting or clicking so hopefully it's just the switch.

I'm just about to service the bolts and slides on the front brakes so I'll check that vacuum line.

 

[AK49BWL]

Defrost activates the A/C compressor from the middle of floor/windshield on up. That could mess with idle.