Help - only 8 volts from NEW house batteries

[Jupiter]

Thank you guys for taking time to provide your replies. It was not a lack of interest that kept me off-line yesterday.

I have a fair understanding off electrical systems but the complexity of the wiring configuration and the related devices within the system have me baffled. Mark, your LINK to the wiring diagrams is very helpful and I will study further as time permits later today.

I installed the batteries myself and I did take a photo of the battery bank wiring configuration and carefully rewired and tested voltage.

The six (6) batteries are 12 volt. After reading the replies and other related posts, I have a few more checks to investigate but I'm confident that the battery bank is wired correctly.

I will report back when I eventually find the culprit which may help someone else down the road.

Thanks again for all your input!

Joopy

[RKins]

Originally Posted by twinboat

A picture of your battery cable arrangement will be helpfull, in case something is mis-wired.

There are 2 jumpers, one between each pair of 6 volt batteries, that should have nothing else, except the jumper on them.

Here is a graphic.Attachment 290610

In this drawing, what do you think he would measure if the black neg cable from ground is landed on the upper battery negative instead of the lower? It's an easy mistake to make and moves the point of reference.

[Jupiter]

BTW - these batteries weigh a whopping 68lbs each and reside in a pit in the basement.

Hope to never do this job again!

[rodekyll]

Did anyone tell him to disconnect the charger until the problem is sorted out? Those poor 6v units are going to look like microwaved potatoes soon.

[l1v3fr33ord1]

Joopy-

That black plastic rectangular thing hanging off the lower-corner negative post is a temperature sensor. Those sensors, when they fail, can create some odd problems. I would remove that sensor before troubleshooting further. It should not be needed for the charging/monitoring system to work correctly.

Just a suggestion, though. Keep us posted.

Happy to hear you have the 12V stock batteries.

[Jupiter]

Originally Posted by l1v3fr33ord1

Joopy-

That black plastic rectangular thing hanging off the lower-corner negative post is a temperature sensor. Those sensors, when they fail, can create some odd problems. I would remove that sensor before troubleshooting further. It should not be needed for the charging/monitoring system to work correctly.

Just a suggestion, though. Keep us posted.

Happy to hear you have the 12V stock batteries.

Thanks for that tip, Mark. That little device was on my list to find out its function. Appreciate the suggestion.

Joopy

[vsheetz]

Compare current to the picture taken of the battery wiring before removal...

[Jupiter]

After once again checking battery bank voltage and block fuses, I then disassemble panels in the basement to access the "manual battery disconnect switch" and the rear of the inverter to check the low voltage out of the inverter. I'm plugged in to shore power so I have 13.5v in and out of the inverter.

I then accessed the rear of the 12 volt panel which requires lifting the bed. The main 12 volt cable into the panel is measuring 13.5 volts.

So, at this point I believe I can eliminate all components on the upstream of the inverter since I have the proper voltage input to the 12 volt distribution panel. Looking at the online wiring diagram the 12 panel has six circuit boards with various relays. My "guess" at this point is that one or more circuit boards are defective. I'm comfortable with basic electrical devices but electronic devices and circuitry is out of my realm of troubleshooting. Next step is to contact the Winnebago rep again to see if they can provide guidance.

More to come...

Joopy

[Milford 47]

Originally Posted by Jupiter

After once again checking battery bank voltage and block fuses, I then disassemble panels in the basement to access the "manual battery disconnect switch" and the rear of the inverter to check the low voltage out of the inverter. I'm plugged in to shore power so I have 13.5v in and out of the inverter.

I then accessed the rear of the 12 volt panel which requires lifting the bed. The main 12 volt cable into the panel is measuring 13.5 volts.

So, at this point I believe I can eliminate all components on the upstream of the inverter since I have the proper voltage input to the 12 volt distribution panel. Looking at the online wiring diagram the 12 panel has six circuit boards with various relays. My "guess" at this point is that one or more circuit boards are defective. I'm comfortable with basic electrical devices but electronic devices and circuitry is out of my realm of troubleshooting. Next step is to contact the Winnebago rep again to see if they can provide guidance.

More to come...

Joopy

If you have 13.5 in those three places this doesn't make sense that 12 volt items don't work

Are your grounds good, loosened, buffed and tightened?

[Jupiter]

The Winnebago rep still couldn't help but referred me to the support at Firefly. Firefly is the system Winny uses for the 12 volt components such as the multiplex switches for lighting; fans; tank monitors; battery monitors; etc.

The rep at Firefly walked me through several troubleshooting steps at the circuit boards behind the panel. It appears was though my "brain" board is fried and perhaps one or two more boards of the six boards. I'm awaiting a proposal for the replacement boards. I appreciated his knowledge and I sure hope this will resolve this most aggravating problem. I will provide the final solution once known.

Again, I really appreciate all the suggestions and support from the good people on this site

cheers,
Joopy

Post Script - I've been motorhoming for about 10 years now with 4 different motorhomes. Three of them Winnebago diesels. I've been to Forest City several times for service over the years. I like Winnebago as a company and their coaches are as good or better than most. HOWEVER, in my opinion the dealer support system is terrible. Trying to get service at regional dealerships is frustrating in terms of wait time. I do most all my own repairs but I would gladly pay for a dealer to fix most of my problems if they could just simply handle the workload in a timely manner. I don't want to start a thread on why they are this way.... just venting my frustration at a common problem that likely (and unfortunately) will not get any better. There.... I feel better

[Milford 47]

What happened to fry the boards and how do you prevent it from happening again?

Most dealer support could be improved but you do hear about some that really try hard

[aether_one]

Originally Posted by rodekyll

Did anyone tell him to disconnect the charger until the problem is sorted out? Those poor 6v units are going to look like microwaved potatoes soon.

Where do you see 6 volt units? The OP has confirmed he has all 12 volt batteries.

[rodekyll]

Yeah, I'd written the comment back before the 12v reveal, but didn't post it till the next day. I should have caught up on the discussion first.

[Jupiter]

After nearly a month of troubleshooting and awaiting parts, I finally resolved the 12v system problem. Without re-reading all the previous posts this thread, here is the condensed version of my issue:

2016 Coach was setting idle in PA for 60+ days after snow birding in FL. Two (2) chassis batteries were down to 9.x volts. Six (6) AGM house batteries were down to 2.x volts. Still don't know why the batteries were drained so I will blame myself for possibly leaving a parasitic draw to occur.

Replaced both the (2) chassis and (6) AGM house batteries. That's right...nearly $1,700 worth of batteries....

Coach started and ran fine, but the 12v house side had very limited availability. Lighting did not function but slides worked. etc. The 12V monitor in the coach "control center" read only 8.x volts.

After much troubleshooting from the source (house battery bank) thru the inverter and to the 12v panel in the bedroom, I determined that I had 12v entering the panel and therefore the problem resided in the panel circuitry.

After a couple conversations with the Winnebago reps, they were out of ideas and referred me to the 12v system manufacturers which is Firefly. There staff was helpful and suggested that I replace 3 of the six (6) circuit boards in the panel. After replacing the boards everything was working EXCEPT the voltage readout still read 8.x volts. I sent the readout board back to Firefly for inspection and testing. It tested fine.

Back to Firefly... after discussing with two different techs, they then realized that they forgot to ship one of the circuit board panels they originally suggested...oops! Shipped and installed the forgotten circuit board and "viola"... the readout is correct and the problem has finally been resolved at a cost for the circuit boards of just under $500.

So, quite an expensive and time consuming resolution to a problem that probably could have been avoided (although I still don't know the actual cause). I appreciated the assistance from the Firefly staff but it sure was aggravating getting to the point of final resolution. I'm providing this update in hopes that others may find this helpful.

cheers,
Joopy