No heat or A/C

[Bwaite27]

Hey y'all. New here. Just inherited my grandfather's '05 Tahoe. Having some trouble getting any temperature change whatsoever from any of the vents. I've done some troubleshooting. It has manual controls (not auto) for driver/passenger sides. The blower works on all speeds. The position selector works on all positions. When I push the temp selectors all the way up, it blows luke warm/ cool air. When I push the temp selectors all the way down, it seems to blow a little harder, but temp doesn't change. I've gone through the recalibration process once. Didn't change anything. I took the cover off under the passenger dash to access the actuator there, it seems to be working. And I can hear the other three when I change their corresponding selectors. Both lines going to heater core get hot and coolant is full. I'm at a loss. Please help!!! Thank you!

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

My initial thought is that you may have a blockage in the heater core. Other members on this Forum that are much more knowledgeable than me will chime in.

 

[swathdiver]

Hey y'all. New here. Just inherited my grandfather's '05 Tahoe. Having some trouble getting any temperature change whatsoever from any of the vents. I've done some troubleshooting. It has manual controls (not auto) for driver/passenger sides. The blower works on all speeds. The position selector works on all positions. When I push the temp selectors all the way up, it blows luke warm/ cool air. When I push the temp selectors all the way down, it seems to blow a little harder, but temp doesn't change. I've gone through the recalibration process once. Didn't change anything. I took the cover off under the passenger dash to access the actuator there, it seems to be working. And I can hear the other three when I change their corresponding selectors. Both lines going to heater core get hot and coolant is full. I'm at a loss. Please help!!! Thank you!

You really need to be a set a gauges on it and see what the high and low side pressures are. You would also use a vacuum pump to check for a leak and use a refrigerant detector to find the leak if the vacuum pump suggests one. Harbor Freight equipment is good enough for this job.

 

[OR VietVet]

Welcome to the forum.

Suspect that like @Joseph Garcia said and @swathdiver said, may have a clogged heater core or a/c problem. I feel you have a blend door hanging up or a failing actuator. Hearing them work does not mean they are working correctly. I think you have some dash tear down ahead of you.

 

[Bwaite27]

@swathdiver @Joseph Garcia @PNW VietVet Thanks guys for the welcome and the insights. And thank you @PNW VietVet for your service. Much obliged. I'll share some pics tomorrow. This is the first forum I've ever joined ever, so if my "forum etiquette" is not up to par, please do let me know. Lol

So my question now is, if the heater core has a blockage, wouldn't the return line not get hot, or AS hot anyway? They both seem to get relatively hot, and also seem to be the same temp. Judging by my trusty hands of course. ?? I was kind of leaning toward a blend door problem, just haven't gotten that far yet. I'll look further into the actuators as well.

I'll look into the A/C aspect of it after I figure out the heat problem. The last few mornings have been a little chilly on my 40 min ride to work at 6am. Lol And I have a 20 month old daughter who I'm sure would appreciate the heat in the coming months. But I'll definitely grab a set of gauges as soon as they're in the budget.

A little history on the vehicle: It belonged to my grandfather (chevy man through and through, taught me a lot). Unfortunately he passed away about 2 1/2 years ago and the truck has been sitting for about a year and a half now. Just put it back on the road about2 weeks ago. It has a few other issues besides the air that I'll mention in a different thread as they're engin related. This truck has a lot of sentimental value and I'd really like to breath some life back into it. Again, thank you all for your help. Looking forward to learning from you and hopefully being able to contribute what little knowledge I have to offer. Thanks!

 

[swathdiver]

@swathdiver @Joseph Garcia @PNW VietVet Thanks guys for the welcome and the insights. And thank you @PNW VietVet for your service. Much obliged. I'll share some pics tomorrow. This is the first forum I've ever joined ever, so if my "forum etiquette" is not up to par, please do let me know. Lol

So my question now is, if the heater core has a blockage, wouldn't the return line not get hot, or AS hot anyway? They both seem to get relatively hot, and also seem to be the same temp. Judging by my trusty hands of course. ?? I was kind of leaning toward a blend door problem, just haven't gotten that far yet. I'll look further into the actuators as well.

I'll look into the A/C aspect of it after I figure out the heat problem. The last few mornings have been a little chilly on my 40 min ride to work at 6am. Lol And I have a 20 month old daughter who I'm sure would appreciate the heat in the coming months. But I'll definitely grab a set of gauges as soon as they're in the budget.

A little history on the vehicle: It belonged to my grandfather (chevy man through and through, taught me a lot). Unfortunately he passed away about 2 1/2 years ago and the truck has been sitting for about a year and a half now. Just put it back on the road about2 weeks ago. It has a few other issues besides the air that I'll mention in a different thread as they're engin related. This truck has a lot of sentimental value and I'd really like to breath some life back into it. Again, thank you all for your help. Looking forward to learning from you and hopefully being able to contribute what little knowledge I have to offer. Thanks!

If there is an issue with the control head or an actuator, the computer will have internal trouble codes stored for them. You need an advanced scan tool, like the Tech-2, to pull these codes and diagnose the system. Whereabouts do you live? I'm in Florida and have one.

 

[Bwaite27]

If there is an issue with the control head or an actuator, the computer will have internal trouble codes stored for them. You need an advanced scan tool, like the Tech-2, to pull these codes and diagnose the system. Whereabouts do you live? I'm in Florida and have one.

Was in Florida for 5 years. West Palm. Moved back to NY a year ago. I'm not very tech savvy, but I know a mechanic or two who might have such a thing. Will definitely ask about it. Thank you

 

[thingraylinetah]

Hey y'all. New here. Just inherited my grandfather's '05 Tahoe. Having some trouble getting any temperature change whatsoever from any of the vents. I've done some troubleshooting. It has manual controls (not auto) for driver/passenger sides. The blower works on all speeds. The position selector works on all positions. When I push the temp selectors all the way up, it blows luke warm/ cool air. When I push the temp selectors all the way down, it seems to blow a little harder, but temp doesn't change. I've gone through the recalibration process once. Didn't change anything. I took the cover off under the passenger dash to access the actuator there, it seems to be working. And I can hear the other three when I change their corresponding selectors. Both lines going to heater core get hot and coolant is full. I'm at a loss. Please help!!! Thank you!

Had this issue in a 1997 blazer I had and it turned out to be a vacuum line under the hood that connected into the adjustment switch in the cab.

 

[Bwaite27]

Had this issue in a 1997 blazer I had and it turned out to be a vacuum line under the hood that connected into the adjustment switch in the cab.

I'll look into it. Thanks!