Heating

[Douglas Friedberg]

looking for some thoughts on heating system controls. Everything functions control wise as it should but iam not getting a very strong blower strength from vents or defroster or floor. Blower motor was changed and sealed and heat is so so. Thermostat was changed I do have problems with temp sending unit it reads way low and gauge as well is reading low. outside mirror temp readings are about 8 degrees higher then actual readings. does heating system rely on these temp sending units to hot air.??? control head is set at 90. i can barely keep windshield clear of fog in cold weather here in Chicago now. In the past systems the heater doors where servo controled i dont know if thats the case with this yukon i would assume so.
Is there a way to check the servo door operations??? Iam asuming fresh air door or such is out of wack or poorly functioning. The recirculation button does work and you can hear the change in operation and feel the somewhat diff in air power but not like it should be blowing to me anyway. So like i said controls do function but the results are piss poor. almost 300,000 miles 2006 slt yukon xl .. The ac does work but not right now as some jack ass seen that i replaced my rear ac lines new shinny alum tubbing that i spliced in and repaired ac system with and unscrewed my fittings and stole my new hand bent lines i made. And while stealing them broke my lines to the rear evaporator as well. Cant win in chicago its either your cat convertors or alum. lines.
Any thoughts would help Thanks and seasons greetings

Douglas

 

[Joseph Garcia]

Did you inspect the resistors in the blower circuit? If not, you may want to check them out and ensure that they are all still working and not burned up.

Yes, there is a way to check/test the blender door operations, but you will need a quality bi-directional scanner like a Tech 2 or an Autel scanner,.

 

[Douglas Friedberg]

Resistors? Are you talking about blower resistor scr controller mounted in blower duct 60 amp ?? YeS have replaced that many times as there is a w water leak from screws of blower box and distroies that once a year. The
Recent
One
Two years old has survived now as I took it apart and siliconed it sealing elTectonics from water damage. Works as it should. Yes I have a top end scanner capeble of uploading and two way commo with modules. 4 K worth of scanner. I understand systems from 1980,s C3 and 1950,s electrical to present times just I don’t work on them everyday like a lot of you guys. Better than tech2. With WiFi.

 

[Douglas Friedberg]

Resistors? Are you talking about blower resistor scr controller mounted in blower duct 60 amp ?? YeS have replaced that many times as there is a w water leak from screws of blower box and distroies that once a year. The
Recent
One
Two years old has survived now as I took it apart and siliconed it sealing elTectonics from water damage. Works as it should. Yes I have a top end scanner capeble of uploading and two way commo with modules. 4 K worth of scanner. I understand systems from 1980,s C3 and 1950,s electrical to present times just I don’t work on them everyday like a lot of you guys. Better than tech2. With WiFi.

Resistors? Are you talking about blower resistor scr controller mounted in blower duct 60 amp ?? YeS have replaced that many times as there is a w water leak from screws of blower box and distroies that once a year. The
Recent
One
Two years old has survived now as I took it apart and siliconed it sealing elTectonics from water damage. Works as it should. Yes I have a top end scanner capeble of uploading and two way commo with modules. 4 K worth of scanner. I understand systems from 1980,s C3 and 1950,s electrical to present times just I don’t work on them everyday like a lot of you guys. Better than tech2. With WiFi.

Just all thumbs with scanner right now don’t get to use it enough.

 

[Douglas Friedberg]

I have a xtool pro smart

 

[OR VietVet]

So, you are saying all blower speeds work? Blend doors are in correct command positions? Does this have a clogged cabin air filter?

 

[Douglas Friedberg]

Oh hell does it have
One
Of those ?? W here is that hiding at never thought about that. Thanks.

 

[OR VietVet]

It lists a cabin air filter for it at RA.

 

[SilverSport]

my 2005 GMC Yukon Denali does not have a cabin air filter despite RockAuto stating there is a replacement filter for one...there is no Cabin Air Filter listed in the owners manual either...

Bill

 

[OR VietVet]

Definitely not normal. Sounds like an overheated bearing in the motors. Can one purchase motors for replacement?

my 2005 GMC Yukon Denali does not have a cabin air filter despite RockAuto stating there is a replacement filter for one...there is no Cabin Air Filter listed in the owners manual either...

Bill

I get that and understand that, BUT, what if the aftermarket add-on has been done and there is a cabin air filter in there. I never assume anything, especially when there is a chance that the CAF option MAY have been done and there is a listing for a CAF.

 

[SilverSport]

good point and should be easy enough to check...

 

[Douglas Friedberg]

No I can’t find and cabin filters in this truck. Thanks everyone for info though