Automotive Air Conditioning Information Forum (Archives)

eastern4by4 on Mon September 26, 2011 8:01 AM

Year: 1985
Make: \\gmc
Model: K2500
Engine Size: 350
Refrigerant Type: R-12
Country of Origin: United States

HI all.
I have a 1985 GMC that had a Wynn's frostemp system installed in 1989.
The A/C still works fine.
The heater core is now leaking and needs to be replaced. The wynn's system in dash evaporator unit incorporates the heater core and evaporator in the same shell.
It looks like I will have to pull the charge and disconnect the evaporator (in the engine compartment) along with disconnecting the heator core in order to pull the box to
gain access to the heater core. This system is really tight inside the dash.
I am open to suggestions for this system as well as a schematic for the evaporator box.
I have considered cutting an access door in the box in order to pull the heater core but would sure like to see a dwg of how it is made inside before cutting it open.
Thanks for any help you can give.

JACK ADAMS on Mon September 26, 2011 1:05 PM

If you can Post some pictures of what you have to work with, this may help one of us to see what you will have to do.

eastern4by4 on Wed September 28, 2011 2:10 PM

I've got to find the correct usb cable to connect the camera.

ASTROENG2011 on Mon July 30, 2012 2:00 PM

If the system you are referring to is a complete under dash system made from vacuum formed plastic and still has the metal heater only blower plenum mounted on the firewall, then the heater core was re-used from the original heater only system that came with the truck. Please note that the system uses the same blower for both a/c and heater modes. If the system has a separate blower inside the instrument panel located above the glove box, then you have the original heater case and it will still take the original heater only core that came in the truck form the factory.

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astroeng2011