Need Help removing Heater/AC box from 72 Roadrunner

[My72Runner]

I have a 1972 Plymouth Roadrunner with A/C. I have reason to believe (it F$^#@%g smells) that there is a mouse nest/carcass in my heater box that I cannot see by removing the fan from the engine bay or the duct work underneath. I'm assuming it must be somewhere proximal to the heater core, which hasn't been changed since we got the car. I was wondering if anybody here has any experience removing heater boxes (with A/C components) from a 72 B-body. From what I've read, it's a pain, and the service manual that I have is less than clear on the topic.

Thanks all for looking. I really appreciate it.

-Mike

 

[WileE]

Before taking anything apart, try fishing wire through the ducts. Block off the intake & plug in a strong shop vac. It could only be dead-leave clump. (Years ago, we had to get out a dead snake inside a customers ductwork... that had to come apart )

 

[My72Runner]

It's got to be a mouse. nothing else makes that dead mice/mice crap smell.

 

[72RoadrunnerGTX]

You will need to pull and split the case halves to get anywhere near the heater core. The heater box can be removed with the dash in place. The 72’ FSM does have step by step instructions for this service, page 24-68. Basically, disconnect the A/C lines and heater hoses, sounds like you already have the fan motor removed. If the drain elbow is still in place, remove it, 4 nuts need to be removed from the engine compartment side of the fire wall. Vacuum supply hose disconnects from the manifold fitting and its grommet pushed back into the passenger compartment. Remove the glove box liner, disconnect wires to the blower motor resistor and vacuum hoses(at the disconnect near the heater control, hose harness comes out with the box). It should then drop down under the dash frame to passenger floor and out.

You will likely find that the foam seals and gaskets, used throughout the heater box, have deteriorated to dust. Be prepared to have to replace them. Jim at Detroit Muscle Technologies reproduces a quality gasket set for that box.

 

[My72Runner]

72RoadrunnerGTX,
Thank you very much for the breakout. Now it doesn't seem so bad! haha
I'm going to try to get it out tonight. I'll post progress/problems later tonight or tomorrow.
Thanks again for your help.

-Mike

 

[My72Runner]

Well, I got more accomplished tonight than I thought I would (wish I could say that more often!)

I got the box out enough to tilt out the top openings and peak inside. Besides a full mouse mansion, I found the culprit- 1 dead mouse. He must have gotten in when I had the car in my main garage during the winter. My best estimate is he's been there about 3 months... sure did stink.

Anyways, threw him outside to warn the others, vacuumed, cleaned the box with disinfectant, and got it all pieces back together before heading inside. Thanks again for all of your help.

-Mike