Electrical Issue

[Oldnacldog]

Hello,
I'm hoping some of the smart folks here can help me out.
We have a 2018 Jayco Seneca 37RB.
Last weekend we realized we didn't have any signal or brake lights on the back of the rig. Along with that, the power steps and power seats didn't work.
It screams bad ground, but I can't find one. All of the grounds under the back end, along with any others I could find look good and solid. I got frustrated, parked it and at that point everything worked! Center light in the back worked to whole time, along with front marker and signal lights.
Any suggestions?
Thanks,
Oldnacldog

[BIGPAPA1970]

You are right….sounds like a bad ground….do you have two fuel tanks or one?

[Oldnacldog]

I have 1-100 gal tank between the frame rails.

[Vicr]

+
Instead of guessing have you used a multimeter at the electrical connections of the devices that aren't working?

[Oldnacldog]

I have not done that but will give it a try.

[BIGPAPA1970]

I believe the 2018.5 Model (Single gas tank) has most of the grounds above the rear hitch. They are poorly secured and will look like they are connected but are actually rusted off. I think Rusty had a good write up on this. For sure a multimeter will help trace it down.

[Rustynuts]

In the future , it’s best to reference you year as 2018.5 as this lets us know you have the S2 chassis. I also have a 2018.5 RB. Here is the thread on redoing the rear grounds on mine. https://www.jaycoowners.com/forums/f...ing-57410.html There are the main ones in the middle, but there are also a set off to the passenger side up under the rear cap and these are to the tail lights. There is also a small group up behind the side entry steps, I would check all these areas for bad grounds. There is also a Hopkins module up under the hitch area that controls the LED tail lights and these commonly can go bad, I carry a spare. Jayco could never supply me with an actual correct wiring diagram that shows and matches all the self resetting breakers in the battery compartment but the steps and power seats come of the bank of the 4 breakers, and I have had 2 of these go bad on me also. Attached are some of the diagrams that I have gathered that may help track it down. Also attached is a picture of the ground bundle up behind the steps, this is after I redid the connections with a grounded bus bar. One of the diagrams is for the 2019 and newer units, but has good easy to trace info on it that is similar to what I have found on my 2018.5. Hopefully some of this info can help.

[Rustynuts]

Forgot this pic, it’s the bundle of grounds on the passenger side back under the rear cap….this is after I redid all the connections onto a grounded bus bar.

[Oldnacldog]

Thank you for all the info. Very good stuff!!
Will keep you posted on how I make out.

[Oldnacldog]

Rustynuts, Thanks again as the diagrams were very helpful, in fact they changed my search for the problem.
Could my battery isolation manager be causing my partial power loss problem. I happened to hear a click (w/ shore power plugged in) from the battery area and my steps, lights worked. At this point all of the circuit breakers had power.
Without shore power, no power to the breakers or to one side of the ISO manager.
Do I need to replace the ISO manger or is there something else that should be sending power to the ISO?
Thanks you,
Oldnacldog

[BobD17]

Sorry this is off topic but Rustynuts this question is for you. Where did you get those wiring schematics? Being a retired aircraft mechanic I would love to find an electrical manual or schematics for my 2021 Seneca. Would make troubleshooting a lot easier. Thanks

[Oldnacldog]

I finally got to the bottom of my problem. There is a 100 amp manual reset breaker buried on the top left back corner of the battery compartment as you look at it. I confess that I had to take it to someone to find it as I was stumped. I don't know yet what tripped it or if it is just getting weak, but I will have a new one on board before we head out again.
Thanks again for all of the help/suggestions.

[Rustynuts]

Originally Posted by BobD17

Sorry this is off topic but Rustynuts this question is for you. Where did you get those wiring schematics? Being a retired aircraft mechanic I would love to find an electrical manual or schematics for my 2021 Seneca. Would make troubleshooting a lot easier. Thanks

I emailed motorized CS and requested them. I asked for all 12v, 120v and chassis wiring diagrams the had available. I usually got them within a week. I also requested the floor, wall, roof and plumbing drawings.

motorizedservice@jayco.com

[BobD17]

Thanks for the information Rusty. I sent an email on Monday to Customer Service requesting wiring schematics and have heard nothing back so far.

[RESQRIQ]

Bob, try again, last night I emailed motorizedservice@jayco.com and requested diagrams and drawing of the different systems I was interested in and had a response this morning to supply my VIN, 10 min after I responded with my VIN I received all of the info I requested.

[BobD17]

Will do.Thanks

[Clarkst]

I have been requesting a diagram for 3 months on and off. Inspired by this post I made another equest today, this time I said pretty please.
Supplied VIN with each request. I suspect the delay is because I mention Newmar in and earlier post..?..

[BobD17]

I tried again and got them (12v electric and plumbing) the same day. My experience with Jayco customer service is it depends on what person you get if they are willing to help you or not.

[Clarkst]

Thsnk you, I will keep at it, I have no other choice.