Not much heat

[curmudge1]

I had this problem last winter & it's still with me. I asked before & didn't get an applicable answer, so I'll try again : 1994 K1500 Blazer w/ 6.5TD doesn't get much heat ouput from the heater, really noticable as it gets colder outside; the colder it is, the less heat comes out. New T-stat last winter (GMC dealer trying to fix this problem), new heater core installed next. Chevy dealer recently looked at it, & said the actuator (heater control: cooler to warmer adjusment) was working, might be an air pocket in the cooling system (??!?). Topped-off coolant & no fix. According the the temp meter in the dash, the engine gets up to temp just as always. Used to be plenty of heat, even in the coldest weather, after the engine got warm, of course.

Anyone have any similar problem that they fixec?
Thanks.

[Diverguy]

I have no idea how cold it gets in West Orange during the winter months but I only have one idea and question. During the really cold few weeks that you experience have you tried a winter front on the truck? Did it help? This is the cheapest help and advice I can provide. Sorry.

[goodmonkey]

I too have had this problem on my 95, but have never had the time to look into it. It doesn't get that cold here in Arkansas, usually between 20 and 40, but it seems that the heater should put out more. When I was at my dad's in Pennsylvania last March, I was driving around when it was about 0 outside, had the heater full blast, running about 45 mph, and still had a coat on. But then again thinking about it, seems like the A/C doesn't get the truck as cold as it should either, but the freon levels are correct. Owning and repairing an old fleet truck is proving to be almost a restoration project.

[moondoggie]

Good Day!

I think your 94 should have the same HVAC box as my 95's. I had to replace the whole box on my pickup as the truck was totaled (previous salvage title) & repaired. The repairs left lots of problems in the HVAC box.

I'd want to differentiate between low temp at HVAC outlets & cold air getting into the cab. That's easy - stick a meat thermometer as far into the heater outlet as you can. 120