Fellow owner of 90's Sero Scotty D350 5.9L Cummins Diesel RV

If the 2 batteries under the hood are the only two, then you’re correct most likely one has been isolated for house use and one start battery.
However that is largely immaterial in figuring out the vehicle charging issue.
Sounds like diagnosis and repair is a bit out of your wheelhouse, so I’d try to find a private shop or maybe a private diesel pickup shop. Not that this is a diesel issue, but anyone who works on diesels has likely been around a 1st Gen Dodge Cummins more than a few times.

Here is a standard basic coach battery wiring diagram.

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30289778/gotomsg/30290025.cfm#30290025

Thank you ALL! The aggregate of responses will lead to my next step (s). And confirmed at least one thing re my mechanic input (who insists that second battery is part pf the starting circuit – I’m getting the rig back today to look further). I brought it to them for brakes, which they did a great job on, but then the charging issues commenced – after they finished on it - followed by them suggesting I needed a new alternator (which I let them replace)….followed by more charging issues which they now indicate they are not comfortable solving. They advise the PCM is now bad. From Dodge/Cummins forum, I’ve read that improper trouble shooting can fry those. Not throwing stones...I’ve been patient….just need to figure out.
“ScottG” thank you especially for your clarification. One battery to start is what I suspected and I’ll now go to the Cummins/Dodge forum to confirm, and get my pics. There has never been a separate house battery in the RV coach portion so that second battery must be for house needs only (not starting).
“Bgum”, Thank you. This is the first I had heard about new company taking over Scotty – all previous input I’ve gathered suggested that Serro plant burned down and business closed. I will pursue your lead.
Appreciate all. As far as a suitable mechanic in this case, I’ve not had a lot of luck. Best electrical Trouble shooter I know (done some amazing stuff on my 98 Saab 900 S), doesn’t have the space set up for RV – but he might take a look in a couple weeks. Current mechanic obviously struggling.
So – one more request. Would appreciate group input on the following:
Would you suggest (if I can’t solve on my own – with input above):
1.) Dodge dealer (not sure their mechanics will have experience with ’92?)
2.) Cummins dealer/service – I’ve seen that they work they work on Class A Diesels…not sure if my Class C is a good fit
3.) A general RV service shop (who understands starting vs house batteries – but maybe not the uniqueness of first gen Dodges as modified by Serro for RV)
Thank you!

Not the unit contact the company.

They are now known as Mobile concepts by Scottie and are in Pennsylvania.

First gen Dodges like your 92 only had one group 31 starting battery - if that helps.

IAMICHABOD wrote:
There is a long running thread on Dodge based RVs You could post your question there and maybe someone there may be of help.

Click Here for that Thread

Good Luck in your quest!

99.9% which aren’t diesels nor the same brand of RV. But doesn’t hurt to try i guess?
OP be more specific with your question/issue. There are a bunch of folks on here that can figure it out very likely.

There is a long running thread on Dodge based RVs You could post your question there and maybe someone there may be of help.

Click Here for that Thread

Good Luck in your quest!

Hello Bgum,
I am the current owner. Inherited it from a family member who is no longer with us. The Serro docs don't have this level of detail, and the Dodge manual, while quite detailed, is unique to the Dodge truck (i.e.; if Serro made any mods with the conversion to RV needs, the Dodge manual will not reflect those.

How to wire up batteries, isolators, Ah requirements, etc, is not really RV specific, so tough to tell if your tech is confused or not.

You should have 2 start batteries under the hood, direct wired in parallel to each other. 'Cause it's a diesel.
House battery(s) presumably are in the coach. They should have a + wire coming from the start battery (or from alternator charging lead or fuse/junction block, however it is configured on your machine), likely with an isolator to keep the house batteries from draining the start batteries.
Additionally, house batteries should also be hooked to your converter and DC fuse panel for the house loads/charging.

Hope this helps.

Why not contact the current owners of Sero Scotty they may have some of the old documents.