I got a new muffler and new rear gas line on my '79 GL I picked up last weekend. Been driving her around. I still can't believe how solid this car feels. Rides really well, aside from the 13" wheels and tiny tires....

 

Anyways, it's been pretty damned cold here in KCMO. We got about 2" of snow today. It's March 21st. I've been trying to wrap my brain around this heater in the car. It seems to warm up my legs just fine, but when I turn on the fan only cold air blows out of the vents. I'm guessing there could be 34 years worth of dust, dirt and debris clogging the air passages from the blower to the vents or from the blower to the heater core to the vents. There seems to be plenty of heat coming from the middle of the dash right next to my legs, so I think the heater core is probably still good. Anyone have a similar experience? How hard is it to start pulling hoses and vacuum all the s*** out of the HVAC system?

 

Thanks!

Simplest way to get at the HVAC system is to remove the dash. Basically drop the steering column, undo the 6 or so bolts and remove the dash. Simple! You will then have compete access to the HVAC system.

 

If you can feel heat I would imagine the problem is the the knob/cable that controls the air distribution through the system. Often the plastic lever that changes the heat setting breaks and the knob/cable no longer changes from hot to cold, this does not seem to be your problem.

 

Also make sure the air is set to 'recirculation' so you are not drawing in outside air (Which I imagine would be bloody cold with 2 inches of snow!).

Edited March 22, 201313 yr by Leeroy

time to rebuild the heater box it makes a huge difference 

Yeah, the white plastic lever whatever you want to call it. That's my guess. The flapper door is not closing to redirect the heat. Toes warm is a great sign. And chances are there's a mouse nest in there if the vehicle sat around more than normal.

 

Might want to install a flush adapter on the heater return hose then back flush it. Check your heater core for leaks or bad corrosion (about to leak). Those are the same as a Dodge Colt so when your search yields zip for Subaru 72-79 cars you can try the Mopar way of life.

I'm going to try running a vacuum cleaner through some of the air vents this weekend to see if anything comes out. I might pull the dash later if that doesn't help. It seems like some hot air is coming through the defroster vents, which seems like a good sign! I bet there's a mouse nest or just 30 years of dirt up in there. 

odds are there full of spoob its been getting crap in the box since new after all