Name this AC part on a 64 Riv, and is it bad

[bodayguy]

This appears to be some sort of vacuum port next to the blower. It's gotten (worse since this pic) to be about 50-50 white on top and stained on the bottom, as if there's moisture in there??

 

A/C is blowing warm. I assume it's related.

 

Help.

[alini]

Its one of the door actuators.  The color doesnt mean anything, the yellowing could be from heat in the engine bay.  If you hook up a clean vacuum line to a port and apply vacuum to it does the arm you see behind it move?  If so its fine.  If this door is not directing air to the right area it may be passing over your heater core instead of the ac unit,

[RivNut]

Check you chassis manual.  It's a dual stage vacuum canister.  One vacuum line opens it half way, the other makes it open completely. The position of the door - determined by vacuum - directs air flow differently.  

 

Ed

[Jim Cannon]

When testing these, the outer port (off center) is the one that moves the door 1/2 way.  Apply vacuum to it and watch the link pull in 1/2 way.

 

When testing for full motion, you need to apply vacuum to both ports, not just the center port.

 

This white unit is not original from 1964, so it has been replaced once already.

 

If air is coming out your dash vents, then this diaphragm is working.

[1965rivgs]

When testing these, the outer port (off center) is the one that moves the door 1/2 way.  Apply vacuum to it and watch the link pull in 1/2 way.

 

When testing for full motion, you need to apply vacuum to both ports, not just the center port.

 

This white unit is not original from 1964, so it has been replaced once already.

 

If air is coming out your dash vents, then this diaphragm is working.

Jim, My impression is the white plastic units are the originals and the later GM replacements are black.

  Tom

[Seafoam65]

                 I believe the black one on my 65 is an original part as it is a 55,000 mile car and everything else under the hood is original.

[1965rivgs]

                 I believe the black one on my 65 is an original part as it is a 55,000 mile car and everything else under the hood is original.

Nope...unless GM used both styles, which I have not once encountered on an original car, the originals were white. Yours was likely replaced with a service part. I have NOS actuators which I purchased before they became disco`d and they are all black. All the period pics I have from magazine road tests at the time show white actuators. Does anyone have any other period documentation to the contrary?

  Tom