hey guys, after driving my pickup for a couple of days (the heater works GOOD in that...) i finally got a chance today to tear my dash apart and fix the heater!
There are 2 things that I did while i was in there, i'm not sure if it was a combination of the 2, or if one was the actual solution and one didn't matter... anyways they both involve the heater core! ...kind of.
I had to remove the glovebox, and i also took off all of the trim on the dash panels, and the lower dash piece which is held on with 10mm head screws. i removed the programmer, and the end cap of the heater box which is just behind the programmer (passenger side). with this panel removed you will be staring at the heater core! it is held in with two 7mm screws and the heater hoses that are out under the hood going through the firewall. I took the screws out, removed the hoses, and took the heater core out of the car. After much snooping around, testing, scratching my head, etc... I came to the conclusion that either the heater core had to be plugged in some of the fins, or the gasket around the heater core was leaking, allowing cold air to bypass the heater core and go directly to the ducts! I flushed the heater core out pretty good and some chunks of "crap" came out. not a lot, but i suppose it could have possibly plugged some of the orifices. Then I put the heater core back in the car (without hooking up the hoses), and turned the fan on high! i felt around the heater core and felt that air was in fact coming through where the foam "gasket" was supposed to seal it in place!!! This would allow cold air to bypass the heater core and go straight through to the vents! Not that much air was leaking, and it actually looked like it fit pretty good, but I took that foam gasket off and put new foam strips on there just to be sure! After flushing the core, and replacing the foam gasket, i put the car back together just to the point that i could test it out. I left it in the driveway running until it warmed up, and when i got back into it...SURPRISE....HEAT!!!!!!!!!!!
It'* a bit of a pain, and it took me about 4 hours from start to finish. Now that you know what you're looking for it should be a little faster. I have pictures of what I'm referring to, and I also have more replacement foam gaskets. email me @ email@example.com
for more information.
I should also mention that i found a red herring during this process! The heater box on the engine side has a note on it saying something to the effect of "to remove barrier cut here" and there is a molded line in the plastic! Well, mine was CUT! I think someone replaced the evaporator before i got the car. Anyways, i thought maybe this was where the cold air was leaking in from because there was no sealant used when it was put back together, just a big slice in the heater box! But upon further investigation from the inside and outside....it turns out that'* just a cover and no air could get in through that slice. Good luck guys!