06 GMC Sierra heater

[FuriousPig]

06 GMC Sierra 4x4 with 76,000 miles. Problem is the heater will not come on when I first get into truck. I know this sounds crazy but it seems like it will start to blow hot air only when I get above 40 mph!! After work for the past 4 weeks I start my truck drive my truck a mile at 30 mph to the main road with only cold air blowing. Hit the main road and accelerate. When I hit about 45mph its starts blowing hot air!! lol yeah weird. On my day off I went to the store then back home, never went above 30mph and it never blew hot air.

The truck does get to normal operating temp (190) pretty quick but still doesnt produce hot air until I reach a speed of about 40mph.

The display lights on the dual thermostat ( hot or cold) switches are intermittant and have been before this problem occured!! I can flick them with my finger and they come on but like I said that has been that way before the heater problem existed.

I know this sounds crazy but any advice is welcome and appreciated!!

[GMCustomerService]

I would recommend taking the vehicle into your local dealership to be diagnosed. They should be able to assist you further and have a plan for addressing the issue. If you have further questions, please feel free to contact me directly. Thank you.

Tricia, GM Customer Service.

[FuriousPig]

Thanks GMCustomerservice. I never thought to take it to the dealer and spend 3 times the money!!

[maxwedge]

I somewhat agree, but maybe not, they should be able to diagnose it and repair on a one time basis, you or an independent without the backround or tech info, could, replace multiple parts and maybe not fix it, just some thoughts on the balance of your options. Plus if the dealer fails to fix it, you have recourse as a return n/c repair. I have noted that this reply from GM customer service is a std boiler plate post. Now remember this comes from a retired GM employee of Cadillac Mtr. Car Div. I would start by seeing if both heater hoses are hot, signaling good coolant circulation.

[FuriousPig]

Your right Maxwedge, I dont have the background or tech info to fix the problems with my vehicles. I wish I had the money to just take it to the dealer and tell them to fix it and have the comfort of knowing it will be fixed when I get it back. I think thats why this website was created and why 1000's of people use it. Soo, the "take it to the dealer" post was annoying to me. Sorry to offend anyone.

Anyway, thanks for the advise Max. I will check the heater hoses and let you know the outcome. Thanks

[FuriousPig]

I checked the heater hoses and they are functioning fine. I dont think its a problem with my coolant or engine heating up. It seems like the mechanism that switchs the air from hot to cold isnt working properly. Once it starts blowing hot air I can switch it back and forth from hot to cold and it works properly.

[BNaylor]

Originally Posted by FuriousPig

I think thats why this website was created and why 1000's of people use it. Soo, the "take it to the dealer" post was annoying to me. Sorry to offend anyone.

I agree. Not an issue and you were entitled to your opinion Tricia from GM Customer Service was annoying. Therefore you did not offend anyone or violate any AF rules. Just so you know she is a topic of discussion with the AF Moderating Staff. I see her posts which mimic spam or at least falls within the definition at other GM related automotive forums and she says the same thing over and over. I believe she means well but is doing what she does based on the interests of GM - Customer Service and the GM dealerships not our membership. More like damage control or public relations since they recently came out of bankruptcy.

Tricia feel free to weigh-in if you disagree or desire to explain your position. Also, feel free to PM me if you would like information on AF's Authorized Vendor Program.