67 Imperial Crown heater help

weirdbeard

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Hey guys. Last year I purchased this car at the Lake Erie Tri State Mopar Club show in Albion Pa. from a private owner. At the time of course all I could see was a cool car. After getting it home I realized someone at some time had taken the interior and dash apart extensively and hastily put it back together.

No interior lights, a couple windows and guages work, radio dead, no heat or a/c or fan. Wires cut, added or spliced. It’s a peach! I’m tackling these issues one at a time. A caliper blew out so that was the first thing. Now the heat.

Previous owner told me the heater core was bad so it was disconnected. That was a treat getting that out. In the struggle to get it out I forgot to mark the vacuum lines from the switch so I don’t know where the lines go on the heater box. My fault.

The other thing is my factory service manual wiring diagram is different than my car for the vacuum switch. The colors are slightly different and the manual doesn’t show a/c (non atc). Does anyone have a vacuum line diagram or wiring diagram for the vacuum switch?

Thanks and sorry for the back story!
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Sorry to hear of the surprises... but good on you for tackling them.

Do you have the genuine factory service manual or a generic? The real one will have an entire section dedicated to Air Conditioning. It's typically found in the back of the factory service manual. There you will find all of the wiring and vacuum diagram specific to AC and Heat, which are different than cars with heat only.

From your picture I can see that there is a big problem (with a potential for fire) with the wiring connections beside the vacuum tubes. This needs to be addressed to prevent a fire. Don't ignore this, and as well, this is an indicator of other electrical overload areas in your wiring harness. You need to go through your dash harness and deal with this. The electrical system in our Chryslers is known for having a design week point in that all of the electricity runs through the amp gauge on the dashboard before being sent off to all the various components. As well it runs through a spade connector on the firewall bulkhead connector, which is a really bad thing. Look into something called the MAD conversion (instructions can be found on this website), which will eliminate this issue and take a lot of the load off the amp gauge and make your entire electrical system much more safe.

Good luck, and don't be hesitant in asking all the questions. The stupidest question is the one someone didn't ask.
 
Thanks. The heater switch is only one of the issues with the wire hacking. That switch is out and I need to find a new one. The used one I have has 3 terminals behind the defrost, heat push buttons not 2. Not sure it will work. I did find the a/c section in the back. The electrical section has the wiring diagrams but doesn’t really show it all like the heater relay, bypass switches on the heater box etc.

The wires that were on the switch are different than the diagram. It calls for a violet which I don’t have. Also I have a light green that is hot which is the feed, but also a black that is hot from the a/c circuit breaker. I have a blue with a white tracer that goes somewhere towards the main harness? It’s just confusing since I can’t follow a diagram.
 
Oops. I looked harder and found vacuum line locations and diagrams for a/c. Thanks for mentioning the a/c section or I wouldn’t have found it!
 
I was just going to say that my service manual is quite detailed. I might have a replacement control switch but it’d be used and untested. What’s the part number on yours?
 
I’m glad I’m back on the site! It’s been a couple years since my email went down and I lost the password for the site.
 
I have these.
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The 3431020 differs from the earlier as shown below in the electrical terminal layout.
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@weirdbeard - the 3rd terminal in your switch has burnt off - AFAIK, they all have 3 terminals. IIRC, the wires should come from the blower motor resistor - low, medium, full on. Additionally (I could be wrong here), in AC cars, when either Defrost or MAX AC is engaged, there's ANOTHER resistor on the AC box itself that's also bypassed, giving the fan that little extra oomph. It's found on the side of the heater box where the heat/defrost/AC door linkages are, and it's "kicked off" by a little linkage arm. Pretty crazy, and definitely leads to puzzlement with wiring diagrams, especially if previous persons have messed with and replaced wiring.

I find it's best to yank the ENTIRE dash harness, labelling connectors as you remove them from their components, lay it out on the work bench and go from there with the diagram. Repair, replace, cleanup, improve (MAD bypass), test, reinstall.
 
@weirdbeard - the 3rd terminal in your switch has burnt off - AFAIK, they all have 3 terminals. IIRC, the wires should come from the blower motor resistor - low, medium, full on. Additionally (I could be wrong here), in AC cars, when the MAX AC is engaged, there's ANOTHER resistor on the AC box itself that's also bypassed, giving the fan that little extra oomph. Definitely leads to puzzlement with wiring diagrams, especially if previous persons have messed with and replaced wiring.

I find it's best to yank the ENTIRE dash harness, labelling connectors as you remove them from their components, lay it out on the work bench and go from there with the diagram. Repair, replace, cleanup, improve (MAD bypass), test, reinstall.
There were only 2 terminals on mine. The one burned off and the other is one terminal with two spades on it.
 
I guess what I’m saying is that there are three terminals for wires but only two contacts. The other style has three separate terminals and contacts.
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