Heat, Slow To Warm Up, Doesn't Blow Hard.

[fedfuzz79]

I have a 2005 Crew Cab w/ the 5.3 liter engine. Truck has the dual zone automatic controls. Heat in truck is very slow to warm up. On cold mornings I can start the truck and let it warm up for 15 minutes and it will barely be warm. However I can get in the truck and drive 5-10 miles and it will warm up just fine. Once the truck gets warm it will roast you out. Also, it doesn't seem to blow all that hard. Which may be part of the problem. In all other vehicles I own and have owned the heater on high sounds like a jet blowing. This truck does not. The only time you can even hear the heat is if you have it set to staight defrost on high. Heater set to vents on high has very little blowing and the back vents hardly blow at all. If you have any ideal what the problem may be please let me know.

 

I have been told to just block off the grill with cardboard, but I do not believe that will help. Like I said the truck will warm up fine if being drove. Also the temps where I live do not get all that cold. Normal morning in the winter are 10's & 20's. Very seldom below zero.

[Jsdirt]

My truck, & all the ones I owned prior make all kinds of heat even below zero ... so I think cardboard is a band-aid instead of a solution ....

 

More than likely the intake for the blower motor is either clogged with tree debris or a mouse nest. How bad depends on what part of the country your from. If you live in the northeast USA, trees & mice are everywhere. I would look there first.

[desrtrat]

check your heater core and see if there is a internal blockage. may need to flush out the cooling system. if your fan IS blowing on fill, and you are getting only a little air out, you may want to get into your heater box and see if the core is clogged with dirt/leaves. after 02, GM stopped putting in cab filters in the trucks, so there could be one of your issues..

 

good luck