2002 Sightseer 30B Electrical Issue

[Mountains R Calling]

Hello Winnie community. We've got a 2002 Winnebago Sightseer 30b that is having electrical issues. I parked it for the winter in November. It ran fine and everything seemed in order. I purchased a battery tender and hooked that up to charge the chassis battery through the winter. I also replaced the ac converter with a progressive dynamics 4600 converter so I could leave it plugged in to shore power through the winter and keep the house batteries charged. I went to start it this past week and all I heard was clicking. It would not turn over. I checked the chassis battery and it did seem charged but it had some leaking and was put in the rig in 2021 by the previous owners. I just replaced it and still just clicks. I tested the live connection at the starter with a light tester and found there to be power at the starter. I decided to unhook the house batteries to confirm there was still power with just the chassis battery and found that there is no power going to the starter with the new chassis battery connected. That dash lights and components are also not receiving power with the chassis battery but they do with the house batteries connected. Do the house batteries provide power to the starter and to the dash board or is this an indication that either there's a bad component within the electrical system or the batteries have been wired incorrectly this whole time? I know there is a switch that allows me to use the house batteries to power the starter in case the chassis battery dies but I did not do anything with that switch. I have not changed the battery configuration since we purchased the vehicle. Could the tender have caused an issue with the chassis wiring. FYI, the battery the previous owners had put in for the chassis was a group 27 deep cycle battery (just like the house batteries). I replaced it with a group 65 vehicle battery. The cable coming off the chassis + terminal has a fuse link which I verified is ok. I've also checked the fuses and relays (and there are a lot of them between the area under the dash and the engine compartment). I don't have a lot of experience with electrical but am hoping it's something I can fix myself. Does anyone have any thoughts on what might be going on and the best way to get to the bottom of this? Some sleep has been lost thinking about this issue. Thanks in advance.

 

[Morich]

The charge setup should not have been a problem. But it does sound like the battery cables got confsued as the choach should not get to the starter except when running or when a dash (boost or aux.??) switch is pushed.
The drawing for this is terrible! Lines that we can hardly read and some go out to nowhere!
So I did some some lines to check!
When looking down on batteries? this shows uit as one chassis/start battery on left and two coach on right when viewed from this direction. Check which side that solenoid in a compartment is on to get straaight? I'm thinking this may be drawn what I might call backward and you are staning on the othere side? Not sure when not looking at RV, so check me on that!!!

Idea is that one geative from chassis bat goes tot he grond on frame and two coach negatives connect together and go to same place as black lines.
Then positive post of coach (red line) has to connect to the solenoid left side. There are likelly to be other cables, so not to move any of those extra. Just talking the main battery cables here! Hard to read this drawing but I know those two cables they show just ending in mid air have to connect to something! Andf one place is the solenoid as it is wht connects chassis to coach battery when driving or when we push the dash switch!
Coach positives have to connect together and then to right side of solenoid as we view it here.
For better view of that solenoid and coach battery disconnect relay:

When we push the dash switch that thyemay call boost, aux or other name, it puts battery on wire labeled LR. That power goes through a coil in the solenoid to ground on wire FM. That closes contacts between chassis on left and coach on right.
check you get chassis bat on left when coach is disconnected, Then when you reconnect coach you should see coach battery on right of solenoid.
Push the dash switch and expect to feel this solenoid thump and see both batteries on left and right at same voltage as they connect together! You get a "jump start" without getting cables out!
Or when you drive power goes the same way and they connect to let you get some charge back into coach batteries as we drive to the next spot!
But you should not get power from the coach batteries to the starter if this relay/solenoid is not closed or stuck!
It's a big set of contacts almost like a silver dollar and we should be able to hear and ffel it thump when you push the switch. If not hearing it, it is possible that the contacts are stuck together??/ Not common but more often they get burned and DON"T make contact to let us charge the coach when driving!
Orange coach and red chassis battery lines should not connect until we drive or push the switch!
Sorry for the terrible drawings but they are backing way down on the good info they used to give us and this is what we now get online!
I see more and more mistakes on them every time I look. Things like those two cables that they drew just going off to the left with no connection????

 

[Mountains R Calling]

Morich,
Thank you for the post and the diagrams. I am grateful for the time you took to assess my situation. You were 100% correct, the battery cables were confused. I was able to determine this based on your diagrams. The set-up was how we received it upon purchase. It had worked until now as my coach batteries were in good shape and able to provide power to the chassis. They had gone bad (they're old) and were not able to provide sufficient power to start the engine. If I had been more knowledgable about the electrical system, I could have figured it out much sooner and without so much stress and anguish . You provided the info I needed to resolve the situation quickly. Thanks again, I truly appreciate it.

 

[Morich]

Good deal! Any time we find the solution I call it progress.