ACC II: Power to climate control amplifier when key is in off position

[Zacharias]

I am just starting to troubleshoot my ACC II (servo) climate control system. I elected to start with some notes I copied off a DIY post, not the factory manual.

I got bogged down at one of the first steps. It says the cc amp should have B+ (battery power) at all times on pin #6 on the cc amp connector. I don't.

It also says it should have B+ on pin #8 when the key is on. I do have power to #8 with the key on.

Questions:

1. where is the power to the amp coming from when the key is off?
2. and/or, any idea what this indicates?

Thing is... this DIY has a list of how things SHOULD check out... but no remedies if they don't.

Tks

[jay_bob]

Link to manual

1971 Chrysler Imperial Auto-Temp 2 Service Reference Guide - Session 281

Pin 6 is the constant B+ to allow the servo to park itself after shutdown. It says there is an inline 1 A fuse for this on Chryslers. However I don't know if MB did it the same way.

I would suspect that Fuse 2 has something to do with it, that is the constant hot accessory fuse on a 123.

Pin 8 is the main power, that is probably sourced from Fuse 8 which is the CC fuse on a 123.

[Zacharias]

Thanks, JayBob.

I located the fuse and it's with the relays in the black box on top of the drivers inner fender wheelhousing.

It's an inline fuse and my holder is empty. It doesn't take a standard fuse, anyone got a pic or a part number by any chance? I am assuming it's some kind of old-style glass fuse?

[cooljjay]

That fuse under the relay cover is the blower motor fuse. I cannot state what fuse it is, it is one of those strange glass beaded filled German fuses....I can tell you that the same fuse is found in the becker radios...

First thing I would check is to see if the aux water pump is free, if it is froze like so many are, then you will also need a new amplifier. Don't forget there is a foam sensor hose behind the glove box, that has turned to dust by now.

[Zacharias]

That fuse cannot be the blower motor fuse, as my blower motor is fine.

As JayBob said, the chart in the manual says it's for the circuit that operates the servo with the ignition key off, so it can go back to its park position when the key is off.

I was going to start another thread on the sensor hose. I can see where it connects under the speaker... but where does the other end connect and to what? I can't see any obvious receptacle.

Thanks

[cooljjay]

Well I know when my blower motor froze the first time it blew that fuse, and wouldn't work until it was replaced. Its possible that fuse controls the amp and that is why my blower motor wasn't working....I won't argue the point, cuz I was never able to find that fuse on the wiring diagrams.

The other end that the sensor tube hooks onto....has usually fallen a bit down...its right about the kick panel, really close to the frame.....if you have the knee panel removed....you will see the plastic tube that runs out the frame for the outside sensor...it y's off that.

[Zacharias]

Originally Posted by cooljjay

The other end that the sensor tube hooks onto....has usually fallen a bit down...its right about the kick panel, really close to the frame.....if you have the knee panel removed....you will see the plastic tube that runs out the frame for the outside sensor...it y's off that.

Finally getting back into this. Tested it with a known good spare blower motor, no luck.

Now for the outside sensor issue:

There isn't anything there that looks like it is supposed to connect up to the intake in the speaker opening.

I DO have a long tube (say 5") with 90 degree bends at each end, one end of which is connected to the junction where the outside air intake comes in. The other end was sitting over toward the center console when I found it.

Is this just some random tube someone stuck on there, or is there a piece or pieces missing in the equation? Not clear how this was ever supposed to facilitate the connection.

Also have two open vacuum lines, one white one black. The white is I believe the intentional bleed line... the black one was hiding. Any ideas on where it lives? I cannot see anything (lots of black sh** under there).

Thanks

[cooljjay]

If you can post a photo of the hose, I can tell you if it is it. I know what it looks like, but finding a photo of it on the net may be hard.

Can't help with the vac lines, all mine were connected so I never looked into that part of the system.

[Zacharias]

I will try and get a pic today.

After I start a new thread for the FUBAR I just accomplished.