Hi all. I'm a noob here and am havin a bit a heater issue. I have a 97 1500 4x4 5.9 that I just bought. I had a new a/c compressor put on this week because the bearing went out on it. Anyways I go to pick it up today and the heater will not blow hot air. It will blow luke warm air, and mildly warm air when on recirculate, but no hot air. This is not good considering the wind chill is hitting -17f here in Cincinnati tonight. I looked through past threads, but can't diagnose. There is no moisture, or fogged windows, or coolent fumes inside the cab so I'm thinking its not the core. The top radiator hose is warm like it should be, but the bottom one is ice cold. When I test drove it it took a while to heat up, but I thought that was normal for a large engine, but I let it run today after I picked it up and it never got hot. The temp guage stays in the norm too.Is it a radiator cap? a bad radiator? something to do with the climate controls? Any help would be greatly appreciated.

Thanks Frank

 

Check to see if both heater hoses are getting hot where they go in the firewall.

 

Cold bottom radiator hose? Does half the radiator stay cool as well? Check to make sure your thermostat isn't stuck. Sounds a lot like mine right before my radiator exploded one single digit temp morning. Half way to work and ca-blam! I thought the frontend fell out of the truck or I hit an invisible deer or something.

 

I have the exact same problem. You describe my problem exactly. Mine started after i change the radiator. That was 2 months ago and still no clue on the problem. wind chill here is 30 below right now. heat would be nice.

 

+1 on the thermostat Aubrey ,,, sound like theres a block sum were if the top hose gets warm but the bottom one didn't.. most of the time is the thermostat, although on my 88 ram it was a bad rad cap, you can go to autozone and they will test the cap for FREE!!!!

 

Thanks for all the help. I went to the local parts store to get the cap tested because I thought that could be the problem. Let me tell ya the story from the beginning. I bought this truck a week and a half a go in Columbus Oh. I picked it up and drove it down to Cincy when I got off the exit I heard a strange grinding noise. Turns out the bearing in the a/c compressor went out. Replaced the compressor and accumulator. Went to pick it up Thursday and had no heat all the way home. Anyway I get to the parts place and I smell coolant, steam rose from under the hood and coolant was dripping. Turns out the guy who sold it to me put stop leak in it. When I drove it back from Columbus the stop leak came loose and blocked the heater core and caused my loss of heat. It also unplugged the leak which the guy failed to mention. Now I need a new timing cover, and it back to the shop. I have owned the truck for a week and a half and have had it running trouble free for about 2 hours. I got hosed.

 

Ok ,so the leak was at the timing cover? Sorry you got screwed! And welcome to DF

 

Yup, it took 15lbs of pressure on the pressure check, but thats where the leaks at. Thanks, glad to be here. Hope to stay too, if unless the rest of the truck falls apart. ha

 

why do you need a new timing cover ? is the old one cracked at the water jacket ?
sorry for your nightmare. welcome to df.

 

I was told I the leak was at the timing cover, so thats whats bein replaced. Its freezin here so i took it to the shop. I don't have a garage so I have to take it somewhere.