I have a 1999 Dodge Ram 1500 4x4 with a 5.2L v8. My issue today is that I have no heat! When I turn the **** to either hot or cold, all I get is room-temperature air. I recently replaced my water pump and my radiator with all new hoses. I was thinking that it could be the thermostat, so I just picked one up and we will see if that does anything. I am thinking that it will not change anything because the engine does not overheat, nor does it take a long time to heat up from a cold start. When I turn on the fan, whether it is on cold or hot, the A/C clutch engages. However, the clutch turns for a second and then stops. It will continue to do this as long as I have the fan turned on. I don't think that the heater core is necessarily bad, because the hoses seem to be fine when the motor runs. Let me know if you want more information from me!
Thanks guys!

 

Define recently? How long ago, how many miles has it been driven?

 

Thermostat will do nothing -- the heater circuit doesn't pass through the thing at all.

Which vents are you directing the heat to when the A/C cycles? If defrost, that's perfectly normal.

I'll bet a dollar that your heater core is plugged up enough that it just cannot provide enough heat to warm the high volume of air passing over it.

 

Pretty funny thing happened to me 3 weeks ago...I thought my heat selector & fan cluster switch was screwed and it turns out it was a cracked **** that just sat and spun around the heat selector dial and I didn't have to do anything but pop a new **** on to it. Of course I noticed this after I had my dash apart and bought a back up heat selector/fan speed cluster.

 

I replaced the water pump and radiator a few weeks ago. The truck has about 165k on it. However, the heat and AC has not worked since I bought it a few months ago.

 

It doesn't matter what vent I direct the heat out of. No matter where I send the air, it doesn't get hot.

 

That sucks! But maybe I will take a look at my *****....Hopefully that is all!

 

Yeah lol, take the **** off and check for any cracks at the base of the plastic **** seat, then try to move the heat adjustor with a pliers once the plastic **** is off. When I was at the junkyard looking at heater controls it seemed to be a pretty common thing for those ***** to be cracked & missing a piece that holds them on, never once did I think it might have been the problem on mine until after I bought a new control panel and tried installing a half hour later lol.

 

It's not the ****, yours is a 97 with a cable operated blend door. The OP's is a 99 which should have an electric motor that operates the blend door. That motor might be bad or he needs one of these. http://www.heatertreater.net/index.html

 

+1 that was the best 35$ I spent. And it can be replaced without cutting out a sestion of the insulation.