Still no heat

[nbro3546]

My car is still pumping out room temperature air AT BEST and not sure what the problem is. Took the glove box out and peeped through one of them holes to see the air mix actuator arm movement and everything moves smoothly when I turn the climate control temperature up and down. Both heater core hoses are hot, it has new thermostat, coolant, and the radiator/overflow tank are all topped off. Blower motor doesn't seem strong like most cars but it really never was. Could my water pump be bad or heater core or a fuse? GM has me at stalemate

[crash93ssei]

If both heater core hoses are hot (not warm, but hot!) Then you have no issue with the fluid part of the system.
You feel air moving out of the vents, that eliminates a blower issue.
The air you feel is only room temperature.... this is an issue and points to a blend door actuator not doing its job correctly. I know you said you checked it, but I would look again to make sure that it is moving through it's full range of motion.

[larry1956]

If u suspect that the blend door actuator is not working properly, take the glove box liner out. You will see the blend door actuator the blend air door lever and connecting the two will be an aluminum rod whose threaded end is clipped into the top of the blend air door lever. With your engine running and up to temperature, you should be able to pop the rod out of the top of the blend door lever and move the lever all the way to one side or the other till you feel hot air coming out of the heater core. Do not try to force the blend air door actuator it self as it is a motor driven, geared assembly. If you feel hot air when you manually move the blend air door, then you need to concentrate on the blend air door actuator. On my car, a 1992 Bonneville with manual controls, as I truned the hot cold switch from cold to hot, I would see about .5vdc to about 12vdc applied to the blend air door actuator connector. The other two wires were 12vdc and blend air ground which is not exactly battery ground but close enough. If you have the proper voltages at the blend air actuator connector, then this is definitely your problem. If you try to move the blend air door actuator lever, it should not move since it is gear driven by a small dc motor. If it does move than one of the gears are broken. On my car, there was a small general purpose diode that had failed. This diode is located on the blend air door actuator circuit board. Replaced it and re-timed the blend air door actuator lever and was goog to go. For those of you who are a little more electrically inclined, you can try to troubleshoot the failure of the blend air door actuator, if you narrow it down to an eletrical problem with circuit board. On my car, the blend air door actuartor circuit board had one IC on it, an L272M dual op amp. This is the heart of a bidirectional motor control circuit. I only had about .5vdc on pin 2, which should been about 12vdc. Traced the circuit back to a bad diode. If you decide to take apart the blend air door actuator, be careful as the housing holds in place several gears as they will fall out if you turn it upside down with cover removed. Good Luck!!

[nbro3546]

Double checked today and everything is moving smoothly. I really don't wanna take this dash apart for nothing :(

[gmman]

do you get cold air when temp is set to 60 degrees (if so this would indicate that y0ur blend gate is moving and could indicate that your blend door is not calibrated). there is an old trick described somewhere in this forum that explains how to disconnect the blend gate and the airmix actuator and substitute a rod (metal coat hanger) into the blend gate. this way you can manually move the blend gate from one stop to the other.

if this does not result in hot air the heater core could be suspect. there might be only a trickle of antifreeze going thru the heater core (enough to make both heater hoses feel warm but not enough to overcome the cold air thru the evap).

if this is the case i guess taking both heater hoses off and using a garden hose check that there is full flow thru the heater core.

[nbro3546]

Kinda hard to describe but the air blows really good through the floor vents (still not warm air). When I switch it to the dash vents it seems like its blocked or something b/c it hardly blows any air. I'm about ready to sell b/c of this STUPID problem

[gmman]

wouldn't give up yet. air flow thru floor greater than flow thru dash vents sounds like a typical problem in the vacuum lines:

1. typical problem, vacuum line from manifold has leak.

2. vacuum reservoir nipple is broken or line has rotted off.

3. vacuum nipples from programmer module have collapsed. there is a fix for this problem in this forum.

[nbro3546]

Hmm I'll check on that tomorrow and post back

[nbro3546]

Update: Today I solved my heat problem and the cause was a little angled rubber hose that hooks to the blower motor into the firewall. When I figured this out I just had to laugh at my stupid self lol. I am pretty surprised that nobody even thought of this but figured this post might help someone else with the same problem. Thanks for all the help ruling stuff out guys and I thank the gods for blessing me with heat again haha