67 Coronet 500 A/C Heater switch

[Bobs67]

I am new to Mopars so be gentle with me! I purchased a replacement switch for the A/C heater. My issue is the old had one double and three single. The new one has five single connections. My issue is how it is wired. I have found a couple of schematics for the old, but nothing for the new. Any help will be greatly appreciated.

 

[Jeremiah]

With a picture of the electrical connections and a part number we can surely help you.

There are basically three things that switch does. 1) supplies power to the fan 2) supplies power to the A/C compressor and 3) creates a vacuum signal for the appropriate dashpot controlling the blend/fresh air/etc. doors in the heater box. At some point after 1967 they changed the operation of these to turn the A/C compressor on with the defroster (as well as "A/C" and "MAX A/C").

Hopefully this will help!

 

[Bobs67]

I did the first one I wrote, but it did not get posted. It was my error. The old no. is:2587564. the new one is:3895790. I have seen a posting that stated the new number is a good replacement. Hopefully that information is correct. As soon as I can figure out how to post pictures, I will put both up.

 

[Jeremiah]

Do you have a digital multimeter that car check resistance or continuity? That will help you figure out what goes where in a hurry.

 

[Bobs67]

View attachment 112438 Here is a picture of the two switches. The top one is P/N: 2587564. The bottom one is P/N: 3895790. I guess that I am looking for the path of least resistance here. Could someone who has already fought the battle with this issue, tell me what color wire goes to what connector? I am sure that someone has already worked thru this issue. Again any help will be appreciated. In answer to the Multi-Meter, no I don't have one with me. This is my "southern" car and most of the stuff I have is back home.

 

[Jeremiah]

The contacts in the middle are for the compressor wires. They are usually green. The contacts to the right are for the fan. Due to variations I have seen with these switches and their functionality I can't tell you what the other three are off the top of my head. If I have some time I'll look at our '66 later this week. Your other option is buying a six dollar multimeter and downloading a wiring diagram.

 

[Bobs67]

Thanks for your help, but I guess that I did not realize sarcasm came with it. LOL As I said before, I have two versions for the top switch just can't find anything for the bottom one. Plus I really don't like the smell of burning wiring. Thanks again for your help.

 

[Jeremiah]

Thanks for your help, but I guess that I did not realize sarcasm came with it. LOL As I said before, I have two versions for the top switch just can't find anything for the bottom one. Plus I really don't like the smell of burning wiring. Thanks again for your help.

Hey I am just trying to avoid spending more time under the dash of this car! If you really need me to I'll check it tonight or tomorrow.

 

[Bobs67]

Again I REALLY do appreciate any help I can get. The big factor I have in my favor is that I have the dash mostly out. There is a 7 pin connector that I am SLOWLY prying loose. Hopefully that will allow me to take the whole thing out. All the wiring for the switch is easy access from the opening. The two wiring schematics I have found and downloaded show only the old switch connections. I guess I was looking for a quick and easy answer. I thought that there should be someone who has already run into this issue and had the answer. If you would look into it when you get a chance I would appreciate it. I also have a Camaro and it seem like it is sooooooooooooooooo much easier to find answers or parts for them. The other issue is I am a "snowbird" and this is the car I have for down here so am very limited in resources. Not whining, just explaining. Thanks again.

 

[Bobs67]

Jeremiah, Just found a switch that is the correct P/N on Ebay. Hopefully you will see this before you have to crawl under the dash. This one has the same connections so hooking it up will not be a problem. Again thanks for your help with this problem.

 

[Jeremiah]

Excellent news!