Some sort of charging issue
It appears that the rear battery is getting short changed
I have had some issues with the diesel not cranking up the way it should.It has been intermittent at best through the winter. I have not had a chance to check out the factory block heater for functionality to see if that will help in cold weather starting. For now I will attack it as a charging / battery issue.
So I decided to tackle it since I had a nice day at hand. I started by taking out both batteries. The main one in the engine compartment and the other on the rear frame. Both are relatively new and premium Group 78 batteries. After taking them in for testing at the local O’Reilly where I work I discovered that the primary battery was actually OK but the rear battery was way run down. They both checked good so I went ahead and got them both fully charged and headed back to the garage.
I made a concerted effort to clean and reset the rear battery ground. It is a simple 12″ cable that bolts to the chassis. After removing the mount bolt I cleaned the contact area down, cleaned the terminal end and remounted the battery and box. And let me tell you, this is no small task. You have to mount the battery into the box and then lift the assembled pair up onto a pair of frame bolts. I have to use a jack to lift them because it is tight and the battery alone weighs in around 40 lbs !
Then I went up front to the engine bay. The van has a 3-way post setup on the core support that splits the feed and battery cables up. It appears that it has never been disassembled or cleaned. So I did it. Now all the cable ends are clean and snug. It didn’t appear to have ant issues but it is better now. After reassembling the cable block I hooked all the batteries back up.
I gave it a test start and run which went off easily. But that is with freshly charged batteries. I will have to give it a road test, maybe tomorrow, and then recheck the battery status to get a better picture on if I did fix the issue. If I did, sweet! If not, then I have more work to do. I am even considering changing out the starter as a preemptive measure. We shall see!