AC mode switch / vacuum troubleshooting

[Michael Babb]

So - after adding a new stereo to my car, the AC is a bit pissed off and will only blow air out in the foot well of the car. I added a double DIN radio, so disconnected this:
center ac.jpg

to keep the center vents from opening . . .but do not think that would jack up the whole system? On initial start, I heard a vacuum hissing, and realized that the mode-switch had become disconnected from the vacuum hoses:
mode switch.jpg

I reconnected the hoses to the mode switch But I still get only foot-well air when I do any vent selection.

Something that I am missing, or recommendation on which hosts to check (and where they are) in case I disconnected another vacuum hose?

Thanks!

[mburshtain]

Take a look at the vacuum connections, they all have numbers and colors.
See attached.

[Michael Babb]

Take a look at the vacuum connections, they all have numbers and colors.
See attached.

Thanks! Have been looking at http://store.delorean.com/c-365-7-3-...-controls.aspx, but that does not go in to detail....and I am not sure where some of those hoses route to. Just printed out your attachment to use to check out the car again.

[mburshtain]

The most common issue is with the rubber seal of the mode switch.
You may need to order a mode control switch rebuild kit -

https://store.delorean.com/p-7759-mo...build-kit.aspx

[Michael Babb]

The most common issue is with the rubber seal of the mode switch.
You may need to order a mode control switch rebuild kit -

https://store.delorean.com/p-7759-mo...build-kit.aspx

was wondering about that as well, but since it worked perfectly before my radio work, I was thinking it was more likely something that I did under the dash....may pull the whole switch to check out the rubber seal itself.

[DMCMW Dave]

Did you do anything else to the vac lines? The vac line to the flap chamber still needs to be hooked up so you don't lose all the vacuum.

Keep in mind that when that flap is closed, it uncovers another hole that will bleed your air off to the windshield - as in defrost. Is your air perhaps coming out of the defrost vents rather than the sides?

You may need to physically block the two unused vents rather than securing the door closed.

[Michael Babb]

Thanks Dave - I did not intentionally do anything to any of the vacuum lines, but did have the whole interior out to work on the radio wiring and cables, so possible that I disconnected something unintentionally. the only thing that I changed with regards to the A/C was disconnecting the lever that opened and closed the center flap.

I checked with a tissue, and I do have some air coming out of the defrost vents. So, I have air on the windscreen and in the foot wells - and this does not change regardless of which mode-switch setting I use. Will try to dig in a bit more this weekend to check vacuum tubes.

[Michael Babb]

Fixed by magic! Got in the car last weekend to go to a St. Patrick's parade, already dreading having no vent air... And the mode selector worked perfectly... Go figure

[DMC5180]

Fixed by magic! Got in the car last weekend to go to a St. Patrick's parade, already dreading having no vent air... And the mode selector worked perfectly... Go figure

When you were doing these operational tests earlier did you have the engine running or just the key ON while playing with the control? If the latter you may have bleed of your vacuum reservoir supply. Your vent doors would be stationary in sort of a default mode. Floor Vents do not require a vacuum to be OPEN. vacuum is needed to OPEN them. Its a Default mode sort-a-speak and is the same (vacuum schematically) as putting the mode switch in the OFF position.

[Michael Babb]

Actually had it running when I was testing...