AC VACUUM SWITCH 2571501 AND 2096084 QUESTIONS

[4spdragtop]

Hi all, trying to wrap up this dash install on our 67 cuda. I bought a replacement ac vacuum switch as one nipple broke and another had previously been repaired. So the replacement I bought was a used 2571501, which "may" be a replacement. I installed it but cant get the blower to come on. I may have gotten wires mixed up as the electrical connectors on the back are different between the 2. No part# on ours but I'm assuming 2096084(from 67 parts book).
Electrical layout is similar but not the same. I dont need the AC to function, but I would like defrost/heat if need be. Anyone know how to test or verify the wiring connections?
Thanks
Steve

 

[Oldmanmopar]

I just ran into the same problem on a 67 Barracuda . I have a 70 and a 71 car here with the newer switch for reference. I will be working on those connections soon. Right now I am installing a map light system and switch so the 67 car has a timed key light, ashtray light,and a map light switch verses coming on with the dome light only. I'll post the findings on those three wires. Also working on installing the rear air on a fastback .

 

[Dana67Dart]

Hi Steve.

You can pinout the new and old switches.

1. Choose one terminal to be the starting point.
2. Attach one lead of your multimeter to it and leave it there for now.
3. Put multimeter in ohms mode
4. Put the switches in the most off position.
5. Touch the other lead to each of the other terminals
6. Note which terminals are open and which have continuity.
7. Now switch one switch and repeat the process
8. After all switch positions have been tested you will know which terminals have closed contacts when the switches are in a particular position.

You can do the same for the vacuum part of it. But with a vacume source (probably a low pressure source would do the same.)

If you can, from the wiring diagram of the 67 and the donor year, determin which wire it the main feed that is helpful.

There might be diodes or resisters in the switch so conducting the same test with the leads reversed will show that and also confirm the pinout


Good luck to you

 

[CodyS]

I just put a new switch in my 69 dart and had a similar problem. The replacement switch would turn the a/c clutch on when I pushed the off button. When I purchased the switch it said the switch was for my 69 dart, and I even looked up the number on the internet to make sure it was right. After I had this issue i did some more digging and found one website that said it was for a C Bodie. That was the only place that said that all other claimed it worked for an A Body. It might be the same number you have there I would have to check.

 

[4spdragtop]

Thanks guys, we didnt install any of the underhood AC stuff when we bought the car, so the AC function isnt needed/used. BUT unfortunately the vacuum switch is needed to divert air flow. Between old vs new harness and attempting "pin out" I'll see what I can figure out.
OH almost forgot...there was a mid year change in the AC wiring....what a cluster literally. Heres pics of 2 different schematics

I just ran into the same problem on a 67 Barracuda . I have a 70 and a 71 car here with the newer switch for reference. I will be working on those connections soon. Right now I am installing a map light system and switch so the 67 car has a timed key light, ashtray light,and a map light switch verses coming on with the dome light only. I'll post the findings on those three wires. Also working on installing the rear air on a fastback .

Hi Steve.

You can pinout the new and old switches.

1. Choose one terminal to be the starting point.
2. Attach one lead of your multimeter to it and leave it there for now.
3. Put multimeter in ohms mode
4. Put the switches in the most off position.
5. Touch the other lead to each of the other terminals
6. Note which terminals are open and which have continuity.
7. Now switch one switch and repeat the process
8. After all switch positions have been tested you will know which terminals have closed contacts when the switches are in a particular position.

You can do the same for the vacuum part of it. But with a vacume source (probably a low pressure source would do the same.)

If you can, from the wiring diagram of the 67 and the donor year, determin which wire it the main feed that is helpful.

There might be diodes or resisters in the switch so conducting the same test with the leads reversed will show that and also confirm the pinout


Good luck to you

I just put a new switch in my 69 dart and had a similar problem. The replacement switch would turn the a/c clutch on when I pushed the off button. When I purchased the switch it said the switch was for my 69 dart, and I even looked up the number on the internet to make sure it was right. After I had this issue i did some more digging and found one website that said it was for a C Bodie. That was the only place that said that all other claimed it worked for an A Body. It might be the same number you have there I would have to check.

 

[4spdragtop]

67 GTX Heat and AC Controls

 

[cudamark]

The vacuum control is separate from the electric control. The electrical part operates the fan motor and A/C compressor clutch, and is just a simple mechanical switch. The vacuum control works all the servo flaps, and in most models, the water valve under the hood. Any vacuum leak (broken nipples or bad slide valve/switch) can result in nothing working vacuum-wise. The internal slide wafers are what move the two switches. They can jamb, break, get gummed up, and cause all sorts of problems. It's also very common for the plastic rivets to break off the back by people pushing too hard on the buttons. I always tried to match the part numbers when interchanging those controls to avoid the problems that you're having. As D67D mentioned, you can test the different wire terminals and maybe find ones that can be used with your application.

 

[4spdragtop]

Ok so I think I figured this out somewhat. As I mentioned I dont need the ac aspect of it, but unfortunately it all comes as 1 switch with 2 components. So I had bought an NOS 3502126, physically the layout compared to 2571501 was the same. I couldnt find an original with the same layout as 2096084.
I used/compared schematics and here is a pic of what I did. Do so at your own risk.
Another question...my NOS 3502126...the mount holes in the plastic arent threaded?? Are the screws supposed to make threads when mounting for 1st time? Kinda like self tapping. Any NOS ones I've searched appear to be unthreaded.
Thanks
Steve

 

[cudamark]

The part numbers I have in my books are 2096084 in the '66 factory parts manual, and 2820487 in the '68 factory parts manual. I'm sure they probably made a later replacement that fit several years and models with some modifications. The later ones definitely have some better plastic!

 

[67Dart273]

I think you're on the right track. Referring to the diagrams in the manuals, there can only be "so many" changes.