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Smitchell · 07-28-2022, 06:52 PM

This is going to be a long post to document issues surrounding the Power Distribution Module (aka PDM) on a 2018 Newmar Ventana. We purchased the vehicle last fall and had it inspected. It passed with flying colors but once we got the rig home I noticed a green extension cord (14 gauge) running from stem to stern on the rig. I thought it might’ve been the previous owners attempt to somehow rig stationary solar so I removed it (it was running from the passenger side headlight back to the wiring harness on the rear bumper). Imagine my surprise after I disconnected the wires and we were getting ready to take our maiden voyage that the brake lights, turn signals, and flashers on the rear of the coach we’re not working. Hence, our first experience with a failed PDM. It turns out that some genius knew how to rig the lights from the front to the rear and got them working bypassing the failed PDM. After checking the serial number on our PDM and realizing that it was part of the failed series of PDM‘s we purchased one at our local Freightliner dealer and installed it. Pretty straightforward other than the fact that Freightliner refused to reimburse us. We are working on that issue now! FYI, the latest set of failed PDMs have serial numbers below 18106398 vice the original recall number below 18103500 (Easy to locate as it’s on the side of the PDM, see pic). That number may have been updated but the latest information I had from the NHSTA gave the updated 18106398 serial number. Fast forward six months and a couple of trips when all of a sudden the same symptoms reappeared (rear lights failed). Off to our local Freightliner dealer that diagnosed a failed chassis distribution module (part number A66-03087-000) that is fed from the rear PDM. The rear CHM failure mimics a failed PDM. Since we were carrying bikes we bought a set of LED lights to plug into the tow plug but it turns out that power to that plug comes from the chassis module. The failed part has been superseded with an updated part (#A66-19809-000), however, they have been on back order since January 2022 (no surprise since it’s loaded with semiconductor chips). It turns out that a failed screw clamp on the cooling system hoses located above the CHM somehow caused coolant to get sucked into the CHM. I say that because the CHM is mounted on a horizontal plate and the five connectors plug into it vertically (The rear CHM is located inside the frame rail on the driver side just forward of the rear axle). When the failed CHM was removed, we pried it open and found it pretty much saturated with engine coolant which caused the failure. Because there was no part availability we, actually my wife a.k.a. “bulldog”, scrounged around and found a chassis module off of a wrecked Freightliner that miraculously worked and we were back on the road! I have attached some pics of the CHM as well as the PDM. Thanks to everyone that chimed in trying to help us diagnose a potential bypass! irv2 folks are the best!

Skip426 · 07-28-2022, 07:50 PM

Great information for newer chassis owners.

The more I read about issues with the new technology, the more I am determined to keep my vintage coach running, even though some of the modules are obsolete.

ernieh · 07-30-2022, 03:48 PM

I assume that most are aware that FL apparently has given up on supplying good PDMs and now has a harness that bypasses the failing part of the rear PDM. Just had mine installed 10 days ago.

alank · 08-09-2022, 05:26 PM

I don't think Freightliner (Eaton makes the PDM) has given up on supplying good PDM's, I think new chassis are being produced with good PDM's now that they have identified the problem.
However, I think is significantly less expensive (don't like to call a company cheap) to add the wiring harness which fixes the old PDM problem, rather than providing a new PDM.