A/C and heater connections

[Deputy]

Hi?
So I'm new to CBodys all I've had have been trucks.. I recently got a 65 fury 3 with a 383. It's a factory ac car it has the model 953 under the dash unit. When I got it, it was disassembled and in the trunk. I fixed the heater core and got it back together and mounted in the car. I just am not sure on a few connections.

I found the here wire plug that goes from the switch to the resistor, however I have a few spots on the resistor that don't have a plug on them. I also have two plugs that come out of the passenger side of the box where the evaporator is but I am not sure that they plug into.
The blower motor turns on but only on low. I've looked at the wiring diagram but I can't seem to find the wires I'm looking for. Does anyone know or have an idea what I'm looking for her to get it back up and running?
Any help is greatly appreciated
JD

 

[Polara_500]

Here's the factory AC supplement schematic, does this help?

 

[Davea Lux]

Hi?
So I'm new to CBodys all I've had have been trucks.. I recently got a 65 fury 3 with a 383. It's a factory ac car it has the model 953 under the dash unit. When I got it, it was disassembled and in the trunk. I fixed the heater core and got it back together and mounted in the car. I just am not sure on a few connections.

I found the here wire plug that goes from the switch to the resistor, however I have a few spots on the resistor that don't have a plug on them. I also have two plugs that come out of the passenger side of the box where the evaporator is but I am not sure that they plug into.
The blower motor turns on but only on low. I've looked at the wiring diagram but I can't seem to find the wires I'm looking for. Does anyone know or have an idea what I'm looking for her to get it back up and running?
Any help is greatly appreciated
JD

Are you sure this is a factory installed unit? Most under dash units were a dealer installed option that were available from several different manufacturers. If that is the case, you are probably missing the short harness that came with the dealer installed unit. The factory unit fits up inside of the dash with the heater core and A/C evaporator incorporated into the same box. It will also have vacuum motors and a vacuum harness to control air flow.

Dave

 

[Deputy]

Polara thata helps out a lot !
Yes it's the factory unit I'm sorry I should have been clearer in my descriptions. It does fit up in the dash between the fire wall and dash.
If I can't figure it out from he diagram I'm sure I'll be asking for more help

 

[Davea Lux]

Polara thata helps out a lot !
Yes it's the factory unit I'm sorry I should have been clearer in my descriptions. It does fit up in the dash between the fire wall and dash.
If I can't figure it out from he diagram I'm sure I'll be asking for more help

A word of caution on any system that has been disconnected for any length of time.
This system was designed for R-12. The oil used to lubricate R-12 systems will turn to jello if left exposed to moisture in the air for an extended period. That probably means that your evaporator, condenser, filter dryer and compressor now have jellied oil in them that will have to be flushed out before recharging the system and attempting to run it. R-12 has been out of production for about 25 years now and it is getting hard to find a shop that will still service R-12 units. As a practical matter, you may have to convert to R-134a which makes getting all of the old oil out of your system even more vital. The R-12 and R-134a oils are not compatible. You will have to replace all of the rubber hoses and o rings as well. R-134a is a smaller gas molecule that will go right past the o rings and hoses that are on your current system. If you can find a shop that does R-12 work, I would suggest going that route, even though it is expensive, because of all the reliability issues with a R-134a conversion. Reciprocating compressors such as the RV-2 unit installed on you fury usually burn out due to oil recovery problems with R-134a. The lighter gas molecule does not push oil thru the system as well as R-12.

Dave

 

[Deputy]

Thanks for the info! I've had a similar system befor on a 74 dodge truck so I'm familiar with the r12 and the 134 issues. Just wondering though what would be a good solution to flush the system out? I'm more concerned with the heater for now since we are getting into the winter months but being here in southern NM it won't be long before I'm looking at the a/c part of it

 

[Davea Lux]

Most of the oil will probably be in the filter dryer and the condenser. The filter dryer will have to be replaced in any case so that will take care of itself. Flushing the system with nitrogen will get a lot of the old oil out, have a good shop do this. If the system is then thoroughly evacuated, most of the time that will be good enough. In severe cases the condenser may need to hot tanked and then purged with nitrogen or replaced with a heavier unit if you go the R-134a route. A new shaft seal and gaskets should be installed in the compressor prior to evacuation as the old seals have probably dried out and are leaking, this will also give the tech a chance to inspect the innards. If the compressor has suffered a burn out, the condenser is probably full of metal shavings and will have to be well cleaned or replaced. It usually will be easier and cheaper in that case to just replace it. After the system is repaired and cleaned up it then should be charged with the appropriate oil. It would be a good idea to update the expansion valve with one calibrated for R-134a if you are changing gases as the system will still work with the R-12 valve but will be more efficient with the updated expansion valve.

Dave

 

[CBODY67]

There is a very simple adjustment of the EPR valve to return a prior R-12 system to R-12 level performance with R-134a gas. As noted, R-134a has its own particular oils, but many are now "universal" in nature.

Chrysler/Mopar did make "hang-down" add-on a/c systems back then. They'll have a Chrysler of Mopar logo on them, as the brand name. Their pictures can be found in the accessory parts catalogs from back then. FWIW.

The replacement receiver/driers will probably be shorter than the OEM production item, by observation. Many claim they should be changed every 6 years, for good measure.

When those older Chrysler C-body a/c systems were newer, they would generally work very well in the summer, but when they got near to being 1lb low on gas, then cooling performance would deteriorate slightly, which was a sign they needed some additional gas. That's how it was on lur '66 Newport, which we learned was somewhat typical of Chrysler factory a/c systems back then.

Changing the front compressor seal is a good idea, anyway. With the compressor off, you can also remove the oil pan on it to see what's inside and get all of the accumulated oil out of it. See the factory service manual (as at MyMopar.com) for how much should be put back in it.

With the current climate, you'll not really need the a/c for a while, so you've got some time to get these additional things done.

CBODY67

 

[Deputy]

Update! So the worrying diagram helped a bunch! Turns out the previous owner had a wire that went to the resistor going to the radio which isn’t working anyways... got that plugged and figured out. Is I have all speed for the blower... vacuum switch works well just have to adjus the linkage on the ac box to open the doors correctly... thanks for all he help and info from everybody! I’m sure I’ll be asking more questions as time goes on