Heater trouble on 97 Ram 1500

STRIDERDAV

MEMBER
DODGE RAM

I began this season with poor heat. I decided to get a new heater core. Still poor heat, except when I use recirculate. Recirc. Only blows out vents and fogs windows, but gets about 140 degrees.

I then changed thermostat and leaky water pump. Still poor heat. The old thermostat had some strange black gunk on it, but was working.

I changed the radiator next. Hoses looked good so I did not change them yet. Still poor heat except recirc.

I borrowed point and shoot style temp gun, and checked both heater hoses, and they were the same (about 130 degrees when I checked).

So it seems that the coolant has not changed temp in the core, yet if I use heat at floor, I get only 90 or so degrees no matter how far I go.

The place that did the core can't figure what can be wrong. They say the have never seen a bad heater core, but that is what I come up with.

What else could be the problem? Also, I have no smoke in the exaust and there are no dectable leaks.

Thanks

6 Replies

PASEOCONV

MEMBER
8 POSTS

I had a similar problem on 98 caravan. If it has similar controls, the switch that you slide from hot to cold on your contol panel could be shot. This activates a door that either lets in cool air from outside or hot air from heater core. This cannot be repaired. I went found a junk yard online that sent me a used one for $50 with a 90 day gtee. A new one runs $350 - $500. The way I knew that is was the control panel was because you can run it through a diagnositc mode. On my van you warm up the engine, with the engine running, turn the fan all the way on, set the vent control to dashboard (not defrost and not floor), turn the temp selector all the way to hot. Then I held down the rear wiper and rear window washer buttons simultaneously until all buttons begain flashing. The system will then cycle through heat and A/C taking turns to blow out the floor, the panel and then the defrost vents. When it did this, the air came out nice and hot. That told me that it was not a problem with the door actuator. The whole panel should come out. Check the color of the plug on the panel itself. It seems that Dodge made more color for my panel and if you get the wrong plug, it will connect but not work properly. If you do this, when you connect the new panel you will have to run it through the diagnositc cycle before it will work properly.