Ongoing Coach Electrical Problem

[joey001776]

Greetings. New to forum. I have mediocre DIY skills, so here goes nothing . . .

I own 2013 Thor 24C RV (w/ Ford E350 engine). While running generator, I made big mistake of holding coach battery switch in "on" position to ensure batteries would charge. Dumb move on my part - it's a big no-no for this momentary switch.

From that point forward, could only power coach with generator on, or when on shore power.

Coach batteries charge fully on gen or shore power (confirmed). Flipped generator breaker on and off - works fine and was not tripped. Checked breakers and fuses, all fine. However, would no longer hear the "clunk" whenever I tried flipping coach switch near coach door to use coach batteries.

I have replaced this switch with similar momentary one, then replaced battery solenoid, and lastly replaced automatic transfer switch. Still coach will not power off batteries, but will power normally off generator or off shore power. I can hear the ATS working when I move to generator power or shore power, but still no "clunk" when I try using coach charged batteries.

Any other suggestions? I'd like to dig a little further before I throw in the towel and take it into RV mechanic/electrician. Thanks

 

[16ACE27]

Here's an RV electrical primer:
You have two electrical systems:
AC - just like your house, and
DC - DC can be provided by the house batteries OR the Converter/Charger
The Converter/Charger gets power from the AC side - either SP or the generator if running. The generator does NOT charge the batteries directly.
DC loads include the RV's lighting, water pump, and control power for:
the fridge
furnace
thermostat
and Air Conditioner.

You have likely blown a control power fuse for the battery disconnect solenoid in the Battery Control Center (BCC).

You can not charge the house batteries when on SP or generator and also NOT have DC power from the house batteries when not using SP or generator. The house batteries are either connected to the house DC buss/load center and Converter Charger or they are not.

 

[joey001776]

thank you and pardon my ignorance. Is the battery control center BCC the same as the battery disconnect solenoid?

I was able to locate and replace the battery disconnect solenoid. It was located under panels in the back, near the automatic transfer switch.

I was able to crawl underneath coach and trace the lines from the coach batteries into the RV, to the generator, etc. But I was never able to find any device with a trip switch or fuse. There was a 5 amp fuse connected to the battery disconnect solenoid that I also checked to ensure it wasn't blown. I looked behind all panels inside RV to try to find another device that might be connected to RV, but found nothing. I did not look in or under the engine compartment though.

I appreciate your help.

 

[joey001776]

By the way, I've read many of your posts and you are incredibly helpful. I've learned a lot from reading them beforehand.

 

[PS89]

2013 Thor 24C

What is the NAME of the model? Need complete identification...

 

[joey001776]

Four Winds

 

[16ACE27]

thank you and pardon my ignorance. Is the battery control center BCC the same as the battery disconnect solenoid?

I was able to locate and replace the battery disconnect solenoid. It was located under panels in the back, near the automatic transfer switch.

I was able to crawl underneath coach and trace the lines from the coach batteries into the RV, to the generator, etc. But I was never able to find any device with a trip switch or fuse. There was a 5 amp fuse connected to the battery disconnect solenoid that I also checked to ensure it wasn't blown. I looked behind all panels inside RV to try to find another device that might be connected to RV, but found nothing. I did not look in or under the engine compartment though.

I appreciate your help.

Almost all 2013 Class A models have a BCC under the hood.
But you have a Class C and it sounds like you have a standard remote controlled latching relay to disconnect the house batteries from the house DC load buss and converter/charger.
The 5 amp fuse is what provides power to the remote operating switch (should be labeled USE/STORE) and id usually the issue if the switch is held in one position too long.

Can you take a picture of the battery disconnect solenoid (old or new) where we can see the part number?

The only other devices between the house batteries and the converter/charger are the REVERSE POLARITY fuses in the Power Center in the RV. They are out of line with the other DC fuses and are usually 30 or 40 amp.
And the DC breaker near the house batteries that is usually 50 amp although it may be 70 amp or hidden in a cabinet near the batteries. In your case, under the sink.

The 2013 Thor Owners Manual does not even mention the house battery disconnect but it does talk about the house/chassis battery "Isolator".

Here is a copy of the manual in case you don't have it:

https://www.cruiseamerica.com/media/kjkjhqvw/2013-thor-motor-coach-owners-manual.pdf

 

[joey001776]

16ACE27 - attached are the pics of the original battery disconnect solenoid that I replaced by new but exact device. Thanks for manual - I have and you're right, it says nothing about an "isolator". I've even started reviewing Thor's online electrical diagrams to try to make sense.

Yup, I started by replacing coach battery remote operating switch with same make/model. Got a hold of the original company who directed me to new manufacture who makes exact same switch. Same number of prongs (6), size, etc.

 

[joey001776]

PS - I'll check again under sinks but didn't see any breakers whatsoever before. I'm also checking under hood for BCC.

 

[joey001776]

Duh. Forgot to attach 2 pics.

 

[16ACE27]

Yep. that is the RV Custom Products battery disconnect latching relay. Mine went bad last year and I replaced with the intellect model. But I digress.

Time to make some voltage measurements. Do you have a multimeter and know how to use it?
If so, find a good chassis ground nearby and measure the voltage on each of the big terminals on the side to ground. Both unplugged from SP and plugged in to SP.

Let us know what you get.

 

[joey001776]

The bolt on the right side of pic shows 12v on shore power, left side nothing. Neither show any voltage off shore power, though coach batteries show full charge at 12v

Re-checked under sink an found the device labelled "shortstop" shown in attached pic. With shore power, one side read 12v, other side nothing. Both showed no reading under coach power. Checked attached fuse which was fine (not blown).

 

[joey001776]

16ACE27 - You are a freakin' genius. I played around with the device under the sink, as you suggested earlier, and lo and behold it DOES have a re-set button on the side. This is the darn circuit breaker that I tripped originally. Had I only known!!​

You really are extremely helpful. I've been wracking by brain for weeks!!

 

[16ACE27]

16ACE27 - You are a freakin' genius. I played around with the device under the sink, as you suggested earlier, and lo and behold it DOES have a re-set button on the side. This is the darn circuit breaker that I tripped originally. Had I only known!!​

You really are extremely helpful. I've been wracking by brain for weeks!!

Yeah, I was just going to tell you that's what that device was and how to reset it.

So I guess now you have some spare parts?

 

[dkoldman]

I love to read threads like this. Kudos to the OP. The experience and knowledge gained from you have done is invaluable for a DIYer. I see you helping others in the not to distant future.

 

[joey001776]

16ACE27 - Yes, I have some spare parts but I learned a lot such that next time I can be calm and cool if I run into similar electrical issues. Again, I can thank you enough for your guidance.​

 

[Deadahead-THOR]

Great tread, having issues of my own with house batteries losing power when running generator. I think I’ve garnered enough information to tackle this problem.

Thanks