AC Heater Switch help needed with swap

[Steve-Oh-no!]

Hi.

Really need some help here. My 65 Barracuda has factory AC and I need to replace the control switch. I gave up trying to find a 67 and down switch and took a punt on buying a 68 and up switch.

I knew the wiring terminals were different but I figured that same number of terminals, same functions....

I've been trawling the internet for hours now and am more confused that I was before I started.

Has anyone actually used a late model switch in and early A body? And which wires go to which terminals?

 

[VDART]

what is wrong with your switch-- if it is the vacuum portion-- --it can be rebuilt.

post up a picture of your unit -- & then a fabo member might be able to match one up for you, good luck ,Lawrence

 

[67Dart273]

You can download a later service manual which diagrams the newer switch

The problem is, that I don't have access to wiring docs for a '65 switch, and don't know if '66 is the same or not

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617

Chapter 24 in the 69 manual has a lot of info on control positions and what does whom to them and when

The diagram for 65 may or may not be accurate, I could not see that they specified what models this applies to. The 65 manual is page 24-6

The 66 Dart/ Cornet manual is page 705. That one is consecutively numbered

None of this is specific to 'Cuda which may or may not be different

The diagrams are top to bottom 65, next three is 66, and bottom is 69

 

[Steve-Oh-no!]

Thanks Del, that's just what I was looking for. :cheers:

 

[67Dart273]

Yer very welcome

 

[Steve-Oh-no!]

Ok. Seeing as my old switch was beyond salvation, and armed with a multimeter and the above schematics, I have found that the two terminals that can be traced back to a source of power are simple on/off switches and separate from each other.

On the 1965 switch, the power comes into circuit 1 and is jumped across to circuit 2. When any button OTHER THAN the "off" push button is engaged, the circuits are bridged.

On the 1968 and up switch, each circuit is powered independently (a good idea anyway) and, just like the older switch, when any button OTHER THAN the "off" push button is engaged, the circuits are bridged. Except the newer switch has two "power outputs".

So I can't see any reason (now) why the switch won't work, provided it is wired as per the 1965 diagram. With the exceptions that I'm going to run a separate power lead with fuse to circuit 2 and not use one of the "output" poles on Circuit 1.

The attached diagram shows my thinking. So, fingers crossed it goes into the car in the next couple of days..Stay tuned for whether it works or fails.

 

[67Dart273]

Yeh, LOL I think that was my point. After all, the only thing the switch needs to do is to power up the blower motor and the compressor clutch.

 

[Steve-Oh-no!]

Exactly. But I was rather hoping to find some Mopar Magic when I popped the back off the old switch. Or at least some electrical trickery...

The good news is I saved over $250 by getting the newer switch and not the NOS parts off Ebay, so the drinks are on me if you ever make it Downunder Del!

:drinkers:

Cheers!

 

[67Dart273]

Thanks, but unless I win the lottery the chances are fairly slim, LOL. "Your land" would definately be one on the list of places to visit.

 

[Jim Kueneman]

@67Dart273, I am using a 3502126 on a 66 Valiant and I get the difference in the main power for the blower and have made the necessary jumper. What I don’t have an explanation for is the AC clutch switch is powered in the OFF, MAX AC and AC positions. I thought this was the easy part. Do you have any thoughts.

Jim

 

[67Dart273]

I'd say something is mis-wired or something wrong with the switch. These don't have the "trick" defrost AC like modern vehicles (where the compressor runs when temps are cold, to help dehumidify and defrost.). These old girls should only activate the compressor on call for AC

To tell you the truth, I've not played much with factory AC switches. My old RR had aftermarket "knee knocker" air, and most anything lately (except the 74 Scamp) does not have AC. The Scamp? Well, it's still tarped from winter LOL

 

[Jim Kueneman]

Ok a warning for all... The 3502126 IS FOR AN IMPERIAL and C-BODY..... these cars have much more complex AC systems and this switch for these bodies HAVE THE AC CLUTCH enabled in the off position because there is another switch that cuts power to this switch based on other factors. I popped the back off the switch and eliminated those contacts so it won't have the AC clutch on in the OFF position. The vacuum ports are fine though one actuator I think this switch apply the vacuum opposite so I may have to swap the hoses around on the actuator. All in all it will work but it takes some effort..

Jim