DC Power Woes :(

[jbeletti]

Okay, so I have some DC power issues. Let's solve this and win the Internet today

Symptoms - Round 1 (from 7 days ago and then this morning):

1. *Grinding noise in the hydraulic bay when trying to lift the coach with the front jacks
2. *Grinding noise in the hydraulic bay when trying to Auto-Retract rear 4 jacks once hooked up to the truck

* Notes / Steps Taken for Round 1:

• RV had had trouble lifting with front jacks to get off the truck when we arrived at CG after 6 hours drive
• Replaced both batteries with new ones
• Had coach plugged into 50 amp shore power for 7 days after new batteries installed
• During 7 days of camping, voltmeter inside coach read from 13.x to 14.x throughout the week - indicating that the converter is "likely" working

Symptoms - Round 2 (from this afternoon):

1. Stepped into coach for lunch after 3.5 hours of travel and there was no working DC power inside coach. All systems dead

Steps taken / observations made after Round 2:

• Generator start switch was inop - thinking KIB multiplex system was receiving DC voltage below its minimum requirement
• Voltage at batteries was 11.8
• Voltage at batteries with truck unplugged from coach remained 11.8 (no charge from truck??)
• Thinking 11.8 volts might be enough to start generator and remembering the generator has a local start switch on the unit, I tried and was able to start the generator
• I was able to get the kitchen slide to run out, lights on etc.
• I was NOT able to get the dinette slide out. All power would go out, then return. Just not enough current available

As soon as I submit this thread, I will be attempting to run the kitchen slide back in. I'll be leaving the Inverter off to conserve DC power. I may put a battery charger on the batteries when I arrive in Winnemucca, NV tonight.

Okay - your turn. What is my problem?

My guesses:

1. Missing or inadequate charge from truck
2. Flaky converter that it outputting DC power but not charging house batts at a high enough rate

 

[danemayer]

Jim,

Voltage reading 13V+ for 7 days on shore power would be the converter output, not the batteries, so you may have a tripped manual reset breaker on the buss bar. That would keep the shore power from charging the batteries.

The truck may have to be running to provide power, or maybe it's providing power but isn't enough to keep up with the refrigerator demand and charge the batteries.

Grinding noise at the hydraulics sounds like pump is running but maybe the valves didn't open. Seems like the valves would need less power than the pump motor, so I can't connect the dots on that.

 

[jbeletti]

Jim,

Voltage reading 13V+ for 7 days on shore power would be the converter output, not the batteries, so you may have a tripped manual reset breaker on the buss bar. That would keep the shore power from charging the batteries.

The truck may have to be running to provide power, or maybe it's providing power but isn't enough to keep up with the refrigerator demand and charge the batteries.

Grinding noise at the hydraulics sounds like pump is running but maybe the valves didn't open. Seems like the valves would need less power than the pump motor, so I can't connect the dots on that.

Hi Dan,

Yeah, I checked the manual resettable breaker on the DC bus many times. Not tripped - wish it was that simple.

Truck was running when readings were taken an hour ago. No diff

Wish I knew more about the hydraulic stuff. May need to call LCI to see what the usual cause it. I'm thinking low DC voltage - but what is actually grinding/buzzing?

 

[RDsStudio59]

Truck probably needs to be running to supply power from alternator/batteries thru relay and fuse. Key on check charge fuse for 7 pin to RV in fuse box (see diagram in truck owners manual).

Be safe and well. See you down the road.

 

[travelin2]

DC Power Woes 😞

Jim, experienced same scenario last January, the 4th day on our way south. Same ratchety noise and hydraulics slow and jerky until nothing!! Up to that point I was blaming it on cold stiff fluid as we were in sub freezing temps.
The breaker that failed and I replaced, if your LM is same our BH, is the in-line 50A just off the batteries prior to the cutoff switch.
Test or jump it across the posts. Likely shot!
The grinding is the breaker tripping and attempting to reset IMO.


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[danemayer]

So - have you taken a voltage reading at the batteries while on generator or shore power to see if the 13V is getting through the buss bar and on to the batteries, or where it's getting lost.

 

[esscobra]

agree that charge not getting to batteries- possibly converter charger out- double check the small circuit breakers- with truck connected and running should show higher voltage - 2 times had low voltage- 1 lightning - no power to site- 1 other time when small breaker had tripped and no charge getting to batteries

 

[jbeletti]

Thanks everyone for the replies.

So after we finished lunch (previous post) - having run the generator for about 45 minutes, with it still running, I was able to retract the kitchen slide. Powered off the gen and house voltage (indoors) read 13.5. Smiles. Left Reno.

Tonight, we arrived around at our overnight spot in Winnemucca, NV around 5:15 pm. I am bushed from today's travel, so I don't plan to do any testing tonight. I have a very long pull-through and have no need to disconnect.

As is customary for me on nights like this, I dropped all 6 jacks down. I prefer to drop the 4 rear first, let them touch, then drop the front 2. What I did not do that I often do first, is plug up to 50 amp power. So it turns out I sapped much of what was left in the 2 new batteries, dropping the 6 jacks.

Got inside the coach and neither of the hydraulic slides would go out. In fact, no spinning of the hydro motor at all. The electric bed slide went out fine. Put the battery charger on the terminals on the top of the 2-batt case, turned it on and it showed 24 amps of current draw. Went inside and the 2 hydro slides went out fine.

I'll keep an eye on the charge current to ensure it drops down but will likely leave it on all night and disconnect it only after all slides are in and jacks are up tomorrow. Then disconnect it and disconnect from shore power.

As bad luck would have it, at the Pacific Region Rally, I gave out my last 80 amp auto-reset breaker and a rally or two before that, gave out my last 50 amp auto-reset breakers But I too feel it's a good idea to swap that breaker out when I can, as well as do some additional voltage testing and possibly do an inspection of the converter and some testing of it too.

 

[Oldelevatorman]

Hi Dan,

Yeah, I checked the manual resettable breaker on the DC bus many times. Not tripped - wish it was that simple.

Truck was running when readings were taken an hour ago. No diff

Wish I knew more about the hydraulic stuff. May need to call LCI to see what the usual cause it. I'm thinking low DC voltage - but what is actually grinding/buzzing?

Intermittent sticky solenoid/s. Had that a time or two on hydraulic elevators.


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[Jesstruckn/Jesstalkn]

Jim sorry we were already gone this morning. Golf day.
Wish we could have dug into it and changed out a few breakers.
That noise is the solenoid clicking due to low voltage.
If you have a set of jumper cables, you could put a jumper cable straight from the battery to the center post on the solenoid. That would eliminate any week link in between.
I do think you have a low charge voltage problem just like I do. I've only found 4.8 volts coming from my truck and it's not enough by itself. My solar keeps me going all day but at night it drops off fast.



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[carl.swoyer]

Okay, so I have some DC power issues. Let's solve this and win the Internet today

Symptoms - Round 1 (from 7 days ago and then this morning):

1. *Grinding noise in the hydraulic bay when trying to lift the coach with the front jacks
2. *Grinding noise in the hydraulic bay when trying to Auto-Retract rear 4 jacks once hooked up to the truck

* Notes / Steps Taken for Round 1:

• RV had had trouble lifting with front jacks to get off the truck when we arrived at CG after 6 hours drive
• Replaced both batteries with new ones
• Had coach plugged into 50 amp shore power for 7 days after new batteries installed
• During 7 days of camping, voltmeter inside coach read from 13.x to 14.x throughout the week - indicating that the converter is "likely" working

Symptoms - Round 2 (from this afternoon):

1. Stepped into coach for lunch after 3.5 hours of travel and there was no working DC power inside coach. All systems dead

Steps taken / observations made after Round 2:

• Generator start switch was inop - thinking KIB multiplex system was receiving DC voltage below its minimum requirement
• Voltage at batteries was 11.8
• Voltage at batteries with truck unplugged from coach remained 11.8 (no charge from truck??)
• Thinking 11.8 volts might be enough to start generator and remembering the generator has a local start switch on the unit, I tried and was able to start the generator
• I was able to get the kitchen slide to run out, lights on etc.
• I was NOT able to get the dinette slide out. All power would go out, then return. Just not enough current available

As soon as I submit this thread, I will be attempting to run the kitchen slide back in. I'll be leaving the Inverter off to conserve DC power. I may put a battery charger on the batteries when I arrive in Winnemucca, NV tonight.

Okay - your turn. What is my problem?

My guesses:

1. Missing or inadequate charge from truck
2. Flaky converter that it outputting DC power but not charging house batts at a high enough rate

I'm wondering if you have any loose crimping at the wires end or possibly corrosion on the terminal?
This brings me to "the" question,
What should our trucks charge pin be putting out?
And is the charge pin volts the Same at idle as when running down the road?


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[RDsStudio59]

Around 13.6v and 14.2v respectively.

Be safe and well. See you down the road.

 

[esscobra]

another thing to check is the battery cables inside battery box- first time I opened top to check water levels , the cable just came right out of the lug that was attached to the pass thru on the top of battery box due to poor crimp- I then went thru and re-crimped or replaced all the battery cable connections

 

[Lou_and_Bette]

another thing to check is the battery cables inside battery box- first time I opened top to check water levels , the cable just came right out of the lug that was attached to the pass thru on the top of battery box due to poor crimp- I then went thru and re-crimped or replaced all the battery cable connections

Exactly what I reported on my thread regarding replacing my batteries. The lugs are actually long hex nuts and the one on my negative (ground) lead was close to falling off. I suggested checking these connections be made to your list of “routine” maintenance items.

 

[pegmikef]

Don't know if it applies here, but when I was going through my tribulations with my converter, one simple test to check the converter is to just turn off the batteries If no lights in rig then there is no converter output. The one time my batteries didn't charge off the truck, I thoroughly cleaned all the terminals

 

[carl.swoyer]

Okay, so I have some DC power issues. Let's solve this and win the Internet today

Symptoms - Round 1 (from 7 days ago and then this morning):

1. *Grinding noise in the hydraulic bay when trying to lift the coach with the front jacks
2. *Grinding noise in the hydraulic bay when trying to Auto-Retract rear 4 jacks once hooked up to the truck

* Notes / Steps Taken for Round 1:

• RV had had trouble lifting with front jacks to get off the truck when we arrived at CG after 6 hours drive
• Replaced both batteries with new ones
• Had coach plugged into 50 amp shore power for 7 days after new batteries installed
• During 7 days of camping, voltmeter inside coach read from 13.x to 14.x throughout the week - indicating that the converter is "likely" working

Symptoms - Round 2 (from this afternoon):

1. Stepped into coach for lunch after 3.5 hours of travel and there was no working DC power inside coach. All systems dead

Steps taken / observations made after Round 2:

• Generator start switch was inop - thinking KIB multiplex system was receiving DC voltage below its minimum requirement
• Voltage at batteries was 11.8
• Voltage at batteries with truck unplugged from coach remained 11.8 (no charge from truck??)
• Thinking 11.8 volts might be enough to start generator and remembering the generator has a local start switch on the unit, I tried and was able to start the generator
• I was able to get the kitchen slide to run out, lights on etc.
• I was NOT able to get the dinette slide out. All power would go out, then return. Just not enough current available

As soon as I submit this thread, I will be attempting to run the kitchen slide back in. I'll be leaving the Inverter off to conserve DC power. I may put a battery charger on the batteries when I arrive in Winnemucca, NV tonight.

Okay - your turn. What is my problem?

My guesses:

1. Missing or inadequate charge from truck
2. Flaky converter that it outputting DC power but not charging house batts at a high enough rate

Hi Jim
I was wondering if you have checked out the trombetta valve itself that's inside the generator Bay with your hydraulics.?

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[jbeletti]

Hi Carl,

No - never checked out anything in the hydraulics works. My issue was low voltage and that is now solved. All hydraulics works are working well.*

* I have a leak but that’s for a different thread


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[porthole]

Hi Carl,

No - never checked out anything in the hydraulics works. My issue was low voltage and that is now solved. All hydraulics works are working well.*

* I have a leak but that’s for a different thread


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Just saw this thread - don't see where you posted what the problem was.

New battereis bad?
Bad cables?
Connectors etc?

You can't depend on the truck to charge the batteries in transit, just doesn't have the current at the 7-way (ever look at the 12+ B wire?)
After getting your batteries fully charged and disconnected from the trailer you should let them sit for 30-60 minutes to minimize any surface charge before testing.

 

[carl.swoyer]

Hi Carl,

No - never checked out anything in the hydraulics works. My issue was low voltage and that is now solved. All hydraulics works are working well.*

* I have a leak but that’s for a different thread


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So Jim , what was the fix ?


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[jbeletti]

Just saw this thread - don't see where you posted what the problem was.

New battereis bad?
Bad cables?
Connectors etc?

You can't depend on the truck to charge the batteries in transit, just doesn't have the current at the 7-way (ever look at the 12+ B wire?)
After getting your batteries fully charged and disconnected from the trailer you should let them sit for 30-60 minutes to minimize any surface charge before testing.

Duane - here's a link to my DC power cleanup and upgrade. I can't say with certainty, what exactly was the root of my trouble. I can only say with reasonable certainty that I have solved my issue. The gist of it is that I upgraded the AWG on heavy load leads, removed the hydraulic load from the breaker buss and went directly to the battery and upgraded the hydraulic system breaker to 80 amp.