97 Tahoe HVAC doesn't blow hard

[cniacaris]

I just got my truck and the heating and AC doesn't seem to blow very hard on HI, I've been in other suburbans and tahoes/Blazers and from what I remember they blew really hard, the motor under the glove box sounds like it's blowing a ton of air and working hard but it's just not coming out like I would think, is there a filter that could be clogged or something? Thanks for any help

 

[NVW]

I have this problem in my 3500, I plan to blow air through the heater core. I'm thinking it has plugged with dust over the years.

 

[Will L.]

No filter iirc, but like nvw said they get plugged up. Do you hear it changing speeds with the different settings on the control? If so its disassemble and clean time. Either that or blend door not playing nice, for which its take apart to fix time.

 

[cniacaris]

Thanks for the input guys, anymore suggestions are greatly appreciated as well, I think there must be something clogged, I bought the truck from my dad, he is the orig owner and has put almost 400k on it and he used to have a wire hair terrior (RIP Matice) and she used to lay on the passenger floor or under the seat, with the amount of hair I have already vacuumed out the rest of the truck I wouldn't be surprised if I find a puppy in the chambers somewhere, I have worked on many vehicles mechanically but never touched an HVAC system so it's time to learn =] I'll keep you updated thanks again!

 

[FellowTraveler]

From your description I suspect air-box door motor. There are motors that control airflow through air-box doors at different HVAC controller settings they go bad at times. Then the other gremlin is melted HVAC harness caused by blower motor pulling too many amps and the fuse not working resulting in harness melt 'sometimes it will cause the blower switch to melt slowly other times it can melt big time and envelope other under dash harnesses.'

 

[JayTheCPA]

First: Welcome to TTS!


Not the thing you want to hear, but . . . Am with the others: All indications are that it is probably time for dropping the dash to get at the exchanger and see what is going on. Sorry . . .

While you are there, might consider:
> adding an additional ground wire from the blower to frame / body (as FT mentions).
> adding the 'rattle-stop' brackets when putting the dash back in place.

 

[Steve83]

Click this thumbnail & read the caption:

 

[FellowTraveler]

Click this thumbnail & read the caption:

These servos are what I called motors my setup has 3 of them the one in the center below the HVAC air-box is a bear to change out unless you have very small hands....