I bought a 1997 Ram Van Elk conversion about two months ago. It has fairly low miles (81k) and is extremely clean all around.

Within about a week of purchasing, the van cabin filled with a terrible, biting, burning smell, which dissipated/stopped within about two minutes. The van was fully warmed up, with the heater on. Since then, this burning smell has surprised me at random times, with no apparent source. It has happened when the van was still cold, within 30 seconds of starting, and when the van has been driving reliably for more than 30 minutes.

Here are my observations:
-headlight switch was examined for overloading/melting, no problems observed. Also, I left the dash disassembled until the smell started again. I put my nose right by the switch - nothing particularly burny-smelling there.

-no smell/smoke observed in the engine compartment, only in the cabin

-in the cabin, there is no visible smoke, the smell seems to be detectable first in the driver's seat, while passengers in the rear cannot smell it for a few seconds longer

-Oil and transmission levels are OK, not changing, and the trans fluid looks red and smells normal. The van drives just fine!

-I suspected the accessory lighting switch panel above the windshield, which also contains a little DC to AC transformer for a tiny neon accessory. I took this apart and left it hanging out while still operational. "The Smell" came back and I was able to closely examine the switchboard/transformer while it was happening - nothing appeared to be burning or melting.

-I'm now suspecting the problem has to do with the heating/AC system, although I'm not entirely certain - sometimes the heater works great with no smell. Sometimes the smell happens while the heater continues to work just fine. The smell seems to happen whether the heater is 'heating' or just blowing cool air, and whether the blower is "full blast", "off" or in between. My ideas on possible heater-related culprits: heater blower resistor, coolant leak into heater core, leaves/pine needles stuck in heater intake (that are somehow burning without smoke...?).

The smell is extremely strong, and smells like a mix of burning wood/leaves and melting electrical wiring. It does not smell like burning oil or slipping belts etc, and I'm familiar with these smells/behaviors.

Any insight or experience would be greatly appreciated! Sorry for the long initial post, please offer advice on Dodge Forum etiquette if necessary. I can't wait to enjoy my van without being paranoid that it's about to burst into flames

 

Do you have a powered driver's seat? If so it could be the switch has one of the motors energized until the overload trips. Other than that, don't be too quick to dismiss the belt as the source of the smell. Like you I had a similar experience and ruled out the belt based on the smell, but it actually ended up being the belt. It was slipping because the tensioner wasn't keeping ti tight enough.

 

Hey alloro,

Thanks for the quick reply.
Would the belt be slipping? If it slipped, would I expect to see a change in alternator output, or hear something? Also, I'm not engaging the AC compressor with the controls - only the heater. So, the AC compressor should just be spinning without load/compression.

I'll definitely reexamine by belt(s) though, thanks.

 

Since this can happen when the van is still cold, or within 30 seconds of starting, I've ruled out engine or heater core temperatures as the culprit. Usually when the belt is slipping the voltmeter will drop. If your problem is the tensioner, then turning on the A/C (or defrost) will make the problem show up. Belts like to slip after starting the engine because of the increased load on the alternator to replace the battery power that was just used to run the starter motor.

 

Thanks for the input alloro.

I just looked at the serpentine belt - it looks in good condition, no fraying or strange markings. Do you know how to check the belt tension? It doesn't feel "loose", but I'm not sure what would be "tight enough". I don't see any alternator voltage sag when "The Smell" is happening, but it might not be enough to make a notable difference on my meter, which reads from 8-18 VDC.

I didn't think to mention that I was using both heat and defrost at times, so the AC compressor may have kicked in for that.

Anyone have experience with the heater blower resistor in these vans? Where is it found? Also - is there any way for leaves/debris to get into the heat/cooling ducts? This van had a lot of pine needles in the interior when I bought it - I think it spent a lot of time parked under a tree Maybe that stuff is getting into the heating ducts and getting hot?

Oh, I don't have a power driver's seat, so nothing to fry under there. It's pretty basic conversion van - just a couple of interior reading lights are the only electronic conversion additions. No TV's, fridges, inverters, rear stereos - nothing should be drawing power in the cabin, except what is controlled on the dash.

 

Each time you get the smell is it with the blower motor running? If so and the blower on any speed but high I would pull the blower motor resistor pack and check it for leaves or other debris. I have seen many of these be burning leaves and once in a while paper.

You will find it under the hood on the right side of the HVAC box. It will take less than two minutes to check. It is held in with two screws and you shouldn't need to pull the wiring connector off of it.

 

Hi Mobile,

Your suggestion seems to be the issue - I just pulled the heater blower resistor, which is held by two 5/16" hex head screws, on the right side of the A/C "black box" under the hood. The resistor, which is just a spiral wire (nichrome, maybe) was packed with a bunch of leaves and twigs, and smelled EXACTLY like "The Smell". I think this is the problem - I am pumped!

It looks like there is a lot of leaf debris in the heat/AC "black box", so I'm going to wait until daylight and then shop-vac the bejeezus out of that thing.

Thanks so much for your help! Now I can drive my van without worrying so much!

ArturoB

 

I cleaned mine back on 08 when I bought it and even brushed the AC evaporator and made a difference on the air conditioning as well. If you click on my screen name it will take you to my information page and on the right side you will see some photos of my HVAC box.