95 silverado wiith heater problems. No warm air coming from the floor or the vents. In fact, I have no air flow from the dash vents. and little air from the floor. I checked the climate control door behind the ash tray and left of the glove box. It is working okay. The blend door by the gas pedal does not move when I switch back and forth on the dash control to regulate between upper and lower vents. I believe it is ok according to the electrical check. I did replace the heater coil and it is working good but it did not help my problem even though it was leaking. I am thinking the two push switches ( air circulation, and air cond.) lights once worked, (at least I believe they have a small led light in them to show which one is pushed in) but I see no illumination on either of them, and neither one makes any changes when I push them. As I remember, the air switch used to turn on the air which no longer works. I am thinking that my problem started around the same time these switches quit working. Are they related to my heat problem? I have done a lot of reading on the net and all have different ideas. Some say for sure it is the vacuum hoses, others talk about a transistor that is bad and can only be reached by removing the dash. Ugghhhhh. Not something I want to do. The blower is working great on all speeds and hot water is flowing through the core. I have worked for two days on this problem and have all but given up on ever fixing it. But, I am very persistent and am thinkiing that I will give it one more try by checking out this forum. I would appreciate any help anyone is able to give, including any pictures of what I will be looking for.
Ray

 

The blend door motor is probably your issue. Remove the little motor by the gas pedal. It should have 3 - 7/32" screws. You can then move the bar that the motor rides on by hand. Turn it counterclockwise and that should be air out of the forward vents. Turn it clockwise and that should be defrost. Just remember to put the bar in the location that the control panel is in when you reinstall the motor. Those little motors are known to go bad and strip the gear inside. If your strapped for funds sometimes you can remove the gear and turn it 180 degrees and reinstall it and it will work (since it only uses half of the teeth during use). The last time I bought one it was under $30 at O'reilly's. Besides that is could be a clogged evaporator.
I am going through the same issue on a truck I just purchased. I think I have a clogged evaporator so I am going to try cleaning it to increase air flow. Good luck!!!!

 

Mr. Shamrock; Thanks for your reply. Already did what you suggested and as luck would have it, there was no change in the air flow. I know there should be, but that also has me stumped. It makes sense that would be the problem. I did take it apart and the gears are okay. Any other suggestions would be a welcome sight.
Ray

 

Does the A/C (cold air) blow out of the vents like it is supposed to? There is another motor like the one we are talkng about that switches from A/C to heat. If your blower is working properly, and that motor is operating the doors right then you probably have a clogged evaporator (you said you replaced the heater core). That is why I ask if the A/C blows like it's supposed to, if it does than the evaporator is good. The air hot and cold passes through the evaporator first, but only when the heater is on is the air directed to pass through the heater core via a door controlled by one of the motors. There are 3 motors - one for vent selection, one for hot/cold, and one for fresh or recirculated air.

 

Tks., for the quick reply again. We might be getting closer to the problem, however my ac does not work at all. At least I do not hear or notice the clutch kicking on when I turn it on. But, I will check the evaporator if I can find it. I will let you know what I find.
Ray

 

I am not sure how to reply etc. on this forum, as I am new to it. But just in case I might make a mistake, I am going to re-answer your last reply. We might be getting closer the the problem. My air cond. does not work at all. I do not hear the clutch kicking in. Do I have to solve that problem first. However, I will check the evaporator if I can figure out where it is. tks. again for advice well taken.
Ray

 

Does the air blow out of the vents with the temp control turned to cold. I know you say your A/C does not work, but at least when it is in the A/C mode does the air blow like it should (besides not being cold). That will be a way to test the evaporator as far as if it is clogged or not. If you remove your blower motor you can see the side of the evaporator that usually will be clogged. Let me know what you find.

 

quick question... where's the blower motor?

 

Under the glove box. It has a black cover over it that is shaped like the motor.

 

i will check it out later today