65 Dart Heater AC Fan Problem

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sgrip65

66 Dart GT 273, 65 Dart GT 273 HiPo
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Hello Members. On my 65 Dart Restoration, I have a problem which I have been unable to resolve. Using my push button controls for AC and Heat/Defrost, my fan functions when I am on AC and Max AC, but not on Heat or Defrost. I have three different fan switches, and I have tried them all with the same results. I have a new push button vacuum switch which I purchased from Classic. All of my vacuum hoses have been routed appropriately and double checked....the wiring as well. So I pose the question....what can be wrong? Does the car need to be running to produce vacuum at the dash vacuum switch? Could it be an actuator? I have no clue, so that is why I am asking. Thanks for the help on this puzzle. Much appreciated. sgrip65
 
Hello Members. On my 65 Dart Restoration, I have a problem which I have been unable to resolve. Using my push button controls for AC and Heat/Defrost, my fan functions when I am on AC and Max AC, but not on Heat or Defrost. I have three different fan switches, and I have tried them all with the same results. I have a new push button vacuum switch which I purchased from Classic. All of my vacuum hoses have been routed appropriately and double checked....the wiring as well. So I pose the question....what can be wrong? Does the car need to be running to produce vacuum at the dash vacuum switch? Could it be an actuator? I have no clue, so that is why I am asking. Thanks for the help on this puzzle. Much appreciated. sgrip65

The engine must be running to create vacuum, but I don't think that's your problem.
Note on the wiring diagram below the wiring to the AC & heater vacuum switch. That's where I believe your problem is. Are the wires properly connected and attached properly? The reason I ask is that switch is whaat activates the blower motor when the defrost and heater buttons are pressed. They also control the AC function, but that's working, I'd rule those connections out.

A-C wiring diagram.jpg
 
I have seen differences in the elc connections on the vac switches. The picture with the darker connections and small screws holding switch together came out of my 66 barracuda with a.c.. the other vac switch has a different elc connections. I don't know what the difference is. I tried that switch in my 66 Barracuda and the a.c. did not work. This might be your problem.

20190726_171819.jpg
 
Yes, I did check the wiring and the hose connections all to be correct. When I post my final comments on my 65 Dart Revisited II build.....yes, the car is complete, I will define the problem's fix. Yes, the switches are set up differently for one, and two, my actuators had some vacuum leaks. Wow....lots of hours to figure that one out. Thanks for the tips on figuring this out. sgrip65
 
In 69 the fan is wired differently for heat and a/c. I think one of the blower resistors is in the circuit all the time on heat to make the fan run slower. On a/c there is no resistor in the circuit on high so the fan runs faster on a/c to move the cold air. Replace the blower resistor & see if that helps.
 
In 69 the fan is wired differently for heat and a/c. I think one of the blower resistors is in the circuit all the time on heat to make the fan run slower. On a/c there is no resistor in the circuit on high so the fan runs faster on a/c to move the cold air. Replace the blower resistor & see if that helps.
Thanks Mike. I did ohm that resistor, and all looked well as I was working on the problem. I did resolve the problem as the new switch was wired differently on the tabs....back side. As well, I had a problem with the vacuum actuators. With that said, the AC/heat door would not open and close....this caused the air to continually blow through the AC. Thanks for the tip. sgrip65
 
I have seen differences in the elc connections on the vac switches. The picture with the darker connections and small screws holding switch together came out of my 66 barracuda with a.c.. the other vac switch has a different elc connections. I don't know what the difference is. I tried that switch in my 66 Barracuda and the a.c. did not work. This might be your problem.

View attachment 1715369554
I believe you're right, retractable.
The two push buttons on the original switch went to heat and defrost, or C1/C1B and C4A in the wiring diagram. The new switches have three terminals. I guess you'd have to look at a later model wiring diagram to determine which terminal(s) on the new switch should go to which wire, or just try the various combinations with a voltmeter.
 
I believe you're right, retractable.
The two push buttons on the original switch went to heat and defrost, or C1/C1B and C4A in the wiring diagram. The new switches have three terminals. I guess you'd have to look at a later model wiring diagram to determine which terminal(s) on the new switch should go to which wire, or just try the various combinations with a voltmeter.

Thank you for the tips. Yes, the new switches are different. I used a test light....finally.....to figure it out. All is working well....now. Appreciate the help. This was a new engine build, and I was a bit concerned in running the engine to obtain vacuum. I used my Residential AC Vacuum pump to create the vacuum using the vacuum source line hooked to the pump to provide the vacuum. Thanks. sgrip65
 
Thank you for the tips. Yes, the new switches are different. I used a test light....finally.....to figure it out. All is working well....now. Appreciate the help. This was a new engine build, and I was a bit concerned in running the engine to obtain vacuum. I used my Residential AC Vacuum pump to create the vacuum using the vacuum source line hooked to the pump to provide the vacuum. Thanks. sgrip65
You're welcome, but I will have the same issue when I get my '65 wired, so which terminals did you use. Your solution could save me time and aggravation.
 
You're welcome, but I will have the same issue when I get my '65 wired, so which terminals did you use. Your solution could save me time and aggravation.
I will take some pics today and get those sent off to you. Thanks again. sgrip65
 
You're welcome, but I will have the same issue when I get my '65 wired, so which terminals did you use. Your solution could save me time and aggravation.

Sorry I have not been able to get at the pics and diagrams for you. I will get that done tomorrow for you. Had a bit of an emergency. Thanks for your patience on this. Best sgrip65
 
You're welcome, but I will have the same issue when I get my '65 wired, so which terminals did you use. Your solution could save me time and aggravation.

Hello 65, Again, my apologies for being so long in getting this to you. Regarding the FSM (Field Service Manual), if you look at the diagrams regarding wiring in the 65 vs. the 66, there is a color change on some of the wiring. As well, in the early 65 cars, they used a different fan switch. With that said, the new switches are different than either the OEM 65 or 66 switches. This caused me a lot of headaches, and I hope this will help you when you do yours. In pic 002, the older looking switch is an OEM 65, and the newer looking switch (the one on the top) is the newer switch which I purchased from Classic Industries. As a reference, you will note that the vacuum ports have three in one row, and four in the other. Using the one with three ports, I will call that the bottom of the switch....I will reference, from this point, the new switch in pic 003. To the right of the vacuum ports, on the bottom, (C1A), this is a hot wire from the fuse block which is a light green wire, on the top, directly above the light green wire, (C2), this wire says dark blue, but it is a light blue wire on a 65 vs. dark blue on a 66...this wire goes to the temp control switch....this switch is the switch which is attached to the left side of the AC box....the switch right next to your right knee as you are sitting in the driver seat. On the right side of the vacuum switch there are three terminals, and the one clear to the end of the switch is the hot wire fee called C1B which is, actually, C1 which is the Black with a white tracer. This is a fused wire between C1 and C1B. Next, is where I was having a problem. In Pic 003, there are two remaining terminals, there is one at the bottom of the switch, and there is one opposing C1B/C1. The book calls for the brown wire, C4A to be hooked to the opposing terminal, but when I did that, when I pushed the heat or defrost buttons, I lost power to the fan. I ohmed and test lighted all the wires, switches, and resistors, and all were good. Then, I hooked the brown wire, C4A, to the terminal, among those three, to the lower/bottom terminal, and all worked well. One other point is the vacuum hoses and actuators. When I assembled the dash, I did not test the actuators. I had a problem with the AC/Heat Door not opening and/or closing. It turns out that the Actuator that sits right above the passenger side kick panel is the actuator that operates the AC/Heat open and close door. This actuator, for me, worked in one direction, but not the other. I changed the actuator, and things worked fine. The lines that run this actuator T off, and they also run the water valve which is under the hood on the passenger side. For me, this actuator worked, but at the end of the open or close cycle, the case had a leak which caused a loss of vacuum making the AC/Heat door not to open or close despite changing out that actuator. End story is this, Hook up all the wires as described in the FSM except for the brown wire....hook the brown wire up, on the new switch, as I described; as well, be sure that the vacuum lines are routed as the FSM notes, and check the actuators to be sure that they function. Hose leaks, actuator leaks, and incorrect routing created a real mess for me, and I am glad to be done with that problem. Thank you for your input as I appreciated your time. I wish I knew how to mark the switch terminals as that would make things a bit more easy to understand. I will see what I can do with the computer, and if I can figure that out, I will send a pic with the marked terminals on the new switch. Thanks. sgrip65

65, 66 AC switch 002.JPG


65, 66 AC switch 003.JPG


65, 66 AC switch 004.JPG
 
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