Heat issues

[MoparMcK]

I have a 69 Newport AC car. It has sat for 23 years. I just recently got it back on the road. I am working on getting the heater going. I have a few questions.

The buttons are very tough to push. How do I get them removed to clean them up so they push easier?

Is a replacement fan switch available? This only blows low speed. No matter what speed it is set to. Since the blower motor sounds tough to get to. I will take my chances on replacing the switch first. Since the setup will be removed anyway.

Is there a diagram for the vacuum lines under the hood? I have five lines that are cut. Since I swapped in a mild 440. I never hooked any vacuum lines to the engine. Besides the brake booster. I would like to get the defrost side operating. So I am wondering which line goes where.

 

[Gerald Morris]

You might want to remove the switch and clean it well. Find the FSM for 69 C bodies, and see how to remove the thing. The old FSMs help enormously with this stuff. Get one now. MyMopar has free ones you can download.

Good quality contact cleaner helps me revive all sorts of old electric switches. A fellow called Devin rebuilds old switches. Look on eBay for him.

 

[Jakter]

A bad blower motor resistor will cause the blower to only have one speed.
What speed that would be I'm not sure.

 

[3175375]

The FSM helped me a lot.
I have posted several times regarding the AC and heat for my 69 Fury III vert, ‘Shamu’, here’s one:

Rebuilding the ac/heater control switch

There’s a video on the controls on this forum that is extremely informative. I believe that I referenced, but I am unsure.

Good luck and you’re going to get it!

 

[HWYCRZR]

Not familiar with ‘69 to know if the resistors for the different blower speeds are in the switch or on the heater box (‘68). Usually one speed points to the resistors. Also if your blower motor is shot and drawing a lot of amps, it will burn the resistors (usually coils of wire). Check the FSM there is likely a simple process to check the resistors and switch.

 

[CBODY67]

All the fan switch does is change the circuits going to the particular section of the blower motor resistor, nothing more. The blower motor resistor will always be in the a/c case where moving air from the fan can cool the resistor coils. Easy to find as it has three connectors close to each other, but far enough apart they can be removed individually.

The basic vac source for the hvac will come from a rear intake manifold runner, then go to a vac reservoir under the hood, then through the firewall to the hvac switch, where it will then have several exit points from the switch, then branching out to the hvac case area. To me, the line drawings of the hvac and vac hose routing has always seemed pretty good, fwiw. There should also be a chart in the FSM which details where vac goes when each button on the switch is pushed..

Please keep us posted on your progress.

Happy Holidays,
CBODY67

 

[Gerald Morris]

Not familiar with ‘69 to know if the resistors for the different blower speeds are in the switch or on the heater box (‘68). Usually one speed points to the resistors. Also if your blower motor is shot and drawing a lot of amps, it will burn the resistors (usually coils of wire). Check the FSM there is likely a simple process to check the resistors and switch.

Regardless of where a load resistor would be placed physically, we can TEST the circuit for basic functionality. Given the dearth of freebee documentation for a lot of this stuff, that helps. Here is how I would test for "sanity" in a simple resistance regulated MoPar heater blower motor circuit:

1.) Isolate the motor, label each lead to it, carefully disconnect it, then test the motor first for resistance with a good ohmmeter like a Simpson 260 or a Fluke. Then I would connect the motor to a clean 12VDC supply, run it, note voltage drop across the leads, and estimate the running impedance. If high, I would repair or replace the motor.

2.) I then would start hunting for resistances from switch to motor leads. Then, test voltages supplied by switching. If the motor runs at only one speed, I would expect open resistance on all the lower speed settings. If this is so, I would then remove the resistor, check it in isolation to confirm it is blown. If it is, then replacement would be in order. BUT! If its still good, then test both switches.

3. The variable speed switch is a simple SPMT sort. Test from the hot terminal. Each switched terminal should have near zero resistance. If otherwise, clean, repair or replace. The vacuum switch should bypass the variable speed switch, with a "MAX" and "DEFROST" setting, both of which should permit full current to the motor. Find the hot and output leads/terminals, test. Again, resistance should be minimal. If otherwise, clean, repair or hire Devin.

 

[MoparMcK]

Thanks everyone for the input. First question for right now. What does FSM stand for? ‍. If I know that I can move forward and possibly fix or create more questions.

 

[3175375]

Thanks everyone for the input. First question for right now. What does FSM stand for? ‍. If I know that I can move forward and possibly fix or create more questions.

Factory Service Manual or Shop Manual.

 

[Jakter]

Thanks everyone for the input. First question for right now. What does FSM stand for? ‍. If I know that I can move forward and possibly fix or create more questions.

Factory Service Manual.
Work the switch back and forth a bunch of times.
Often the contacts oxidize from not being used and working the switch back and forth will sometimes getting it working again.
Don't cost anything but a little time.

 

[Gerald Morris]

Thanks everyone for the input. First question for right now. What does FSM stand for? ‍. If I know that I can move forward and possibly fix or create more questions.

Try this: https://www.mymopar.com/downloads/servicemanuals/1969_Plymouth_Service_Manual.zip

Its a free 1969 Plymouth Service Manual. The Fury should be in it, which is a C body vehicle. I strongly suspect your switches and heater will be identical to what is shown there, though I might be wrong. Well worth the look, as its the only 1969 freebee there.

 

[MoparMcK]

Factory Service Manual.
Work the switch back and forth a bunch of times.
Often the contacts oxidize from not being used and working the switch back and forth will sometimes getting it working again.
Don't cost anything but a little time.

I did do this. Back in the days of literally not knowing anything. This is how a lot of stuff was fixed. Haha.

 

[Davea Lux]

Thanks everyone for the input. First question for right now. What does FSM stand for? ‍. If I know that I can move forward and possibly fix or create more questions.

FSM = Field Service Manual

Dave

 

[Gerald Morris]

FSM = Field Service Manual

Dave

Thank you Dave for providing the CORRECT rendition of that abbreviation.