2002 Ram Van No Heat

I've searched through the archives and had no luck so here goes. I have a 2002 Dodge Ram Van B1500 3.9L V6. There is no heat, not even a hint of heat when the engine is hot. I played with the vacuum operated valve on the heater hose and it appears to be working. I even manually moved it to be sure and was unable to get any heat. I think the heater core is clogged... I tried flushing it out with a hose but it didn't work, both the hose going to the core and returning are hot, I'm assuming that the coolant is just passing through the bypass and not the core.

Is there anything I'm missing that could be the cause ? How bad is a heater core to do in this van ? I'm just trying to get a rough idea of what I'm in for. It's getting cold here in NY so I'm moving on this soon.

Ironically I just bought a heater core this morning to change mine. The only place I could find one is at the dealer for almost $300.

There is no bypass within the heater box or the heater core. If both of your hoses are hot, then coolant is passing through the core and your problem is elsewhere. The most likely culprit is that the air blend door actuator is not moving the door to divert air through the core.

Thanks so much for the reply. The only other time I ever had a similar problem was on an old Chevy Impala many years ago. That heater core turned out to have a bypass, I just assumed they all did.

Would a Haynes manual have info on how to get at the air blend door ? Or... should I just trace the duct towards the core ?

Thanks again for the info.

I'm pretty sure that if you remove the glove box door (or at least fold it down by squeezing the back together until the rubber stoppers clear the frame), the air blend motor and linkage are behind it. If you find it and disconnect the linkage, you can manually move the linkage to see if the heat comes up. At least you'll know if you're on the right track. Alternately, run the engine and turn the temperature knob up and down and observe if the linkage moves. If it doesn't move you'll then have to disconnect the linkage and manually operate it, just to make sure it is not frozen in place. But if it did move on it's own, you can rule out the air blend door as the problem.

Don't forget to warm the engine and turn the temperature knob up to open the vacuum controlled water valve when you look for heat.

alloro - that you very much for all your info. You gave me a good blueprint to troubleshoot the problem. I'm going to try and tinker with it on Monday and I'll post something once I get it fixed.

Thanks again !

alloro - you nailed it. I dropped the glove door box and could easily access the linkage you mentioned. That was the problem... I moved the arm and the heat came flowing. It's been cold here in NY so that saved my you know what. I just left it in the position to give me heat and I'll fix it properly once the weather warms up.

Thanks again for the help !

Good, glad to hear that you've got heat! There's nothing worse than knowing that all of that heat is sitting a couple of feet away and you can't have any. :)

Hey I have a 2002 ram van conversion and have had very little to no heat since winter began. I seen another post on here regarding that air diverter and the person said that the rod that controls it is up under the hood above the A/C but you can reach it. According to them the rod had become rusted/corroded and all they did was spray it down with WD-40 and work it back and forth a little and voi la it started working again just fine. As soon as it's light outside I'm heading out to see if mine is caused by the same condition (fingers crossed). Hope that helps as he said it was a two minute fix and ya might not have to wait til spring to do it.

Usually the rust builds up on the portion of the rod that sticks into the engine compartment, not the portion under the dash. Look (with a light) on the top of the air box on the passenger side and you'll see the rod and the arm it's connected to.

I still have the van and never bothered fixing it, it's a work van so as long as I can set it for heat in the winter and AC in the summer I'm happy. In my van all you do is drop the glove box down and it's easy to reach in and slide the lever.

Can someone tell me what the linkage looks like? I have the same issue and just not sure which one to disconnect and move.

Can someone tell me what the linkage looks like? I have the same issue and just not sure which one to disconnect and move.

See about three posts back where Alloro says to take a flash light ...

Guys! I found a kit that repairs the broken blend door problem with no dash removal and takes about an hour. The kit is called the HeaterTreater and they have installation videos on youtube. check it out: www.heatertreater.net

The kit is called the HeaterTreater and they have installation videos on youtube.

HT is old news, try Googling it to see what I mean.