jeepnut47

Anyone have trouble with their 99 defroster clearing the windows? Mine ran for 45 mins last night and barely made a clear spot. It was hot, humid, and pouring the rain. This started last year in the winter. The truck sets around a lot, so I thought it might just be moisture in the cab, but it doesn't seem to matter. My first thought was a leaking heater coil but I have no smell or leak in the floor.


No antifreeze smell, good heat, good airflow, AC doesn't work but compressor works. They did not find a leak the last time they charged it but suspected the evap coil.


Could it be so minor of a leak, that its causing it? I don't notice a film on the windshield. I've tried cleaning it a few times, but still seems to fog up.


$700 to fix it, plus I supply the new dash.


thoughts before I try this myself?


thank you

KATOOM

The defrost works by not only blowing air on the windows but rather running the AC compressor as well. So for the defrost to actually work it needs the evaporator because it removes moisture from the air. So I'm going to make the assumption that because you're having AC issues your defrost wont work any better than it does.

Also, the compressor runs in all HVAC selections but two.

jeepnut47

I agree. Maybe it is all with the evaporator. Today is dry and cool. I tried my defrost and it doesn't fog it up. I kind of wondered if the heater coil was leaking, it would fog it up no matter what.

KATOOM

If the heater core is leaking bad enough to cause moisture buildup on the windows when you turn on the defrost then you should most definitely smell the antifreeze. Smells like foul pancake syrup.

jeepnut47

Yes it should. And the lack of "noticeable" smell is what puzzles me. I'd ask my wife to smell it, but she has no sense of smell.

I could always just be used to it to. And just think it's old truck smell.

After it warmed up, sat in my driveway shut off for about 5 mins. I got back in to move it and the window had started to fog!?!? Turning it on didn't help and made it worse. I turned it to cool and it slowly helped.

Yes one or both of the cores are probably bad. I'm probably just trying to talk myself out of fixing it. Lol. I was trying to wait two more years before really working the truck over but I might have to start earlier. I'm not a dodge fan, but I love my Cummins. I've 225,000 mile on this truck. Everything is well maintained. I only put about 5,000 miles on it a year. It should outlast me.

KATOOM

That does sound like a heater core.....without the smell.

jeepnut47

Thanks so much for the replies.

jeepnut47

Heater core is the confirmed problem. Saw antifreeze in my floorboard yesterday.

KATOOM

Whats your plans to fix it? I ask because there's the full blown take everything apart, including the AC system, which all takes a lot of time and money. Or do it a less involved way which doesnt call for touching the AC system.

I say this lightly because there are some who are very passionate about preforming the whole shebang. But there are others who dont see the point in going through all that work.

jeepnut47

I'm actually paying a local shop to do this one. Replacing both the heater and evaporator cores. I just have to supply a new dash since mine is all cracked up. $700 for the shop to do it.

Most shops around here didn't want to do it though. There is a very good radiator shop everyone recommended. I know I'm capable, but the frustration and time are big reasons not to do it myself. In about 2 years, after the house is built, I probably would do it myself because I'm planning on doing a part restoration and dump bed installation. It just didn't last that long. . It's time to cut wood too, so I need the truck back quick.

I highly considered doing it myself, but I've reached a point in my life I can afford it. Lol. But also, it's a daily work truck and would just like it done quickly. I don't have the tools to charge the ac, so it's got to go to shop at some point.

I was ok with no ac but couldn't go without defrost.

KATOOM

Well at least you're getting taken care of.....

And yeah, its time for cutting wood. Not thrilled about that.

Busboy

Glad you're getting it fixed but without AC you don't really have "defrost" as the AC is needed to strip the moisture from the air or you are just blowing warm moist air onto the cold windshield.

jeepnut47

It hurts to have it done, but I need my truck. . Looking forward to converting to a dump bed some day. Lol. Sure will help with wood.

KATOOM

I still load tons of wood on a flat bed trailer. I'm looking to get a dump trailer soon.