Great input, I'm sure theres more than just me that appreciates and soaks up all this BTDT knowledge.
Update. I have heat & partial defrost!
Atleast I had heat tonight
I only ran the engine for approx 20 minutes but in that time the heat ran me out of the cab. The rheostat/switch is bad so I had to run it hot-wired full blast. The core didn't leak in this test so it's not conclusive that it'll hold up under prolonged use, so I'll be monitorin it closely. I have the manual water valve and it didn't leak when openned up for heat during the test either, so, so far so good
Parts needed to get it back into service is a new switch & defrost duct hose.
In studying the cutouts in the firewall and Denny's pics, I can now see how the fresh air heater mounts. This basic recirc type heater I have has probably been on the truck since new so I'll run it until it breaks.
It doesn't have a separate control for defrost, you get both heat and defrost once you turn the coolant valve on and the fan switch on. basic but it'll do for now.
I can see a fresh air heater w/an electric coolant valve one day perhaps
Dave
