Keystone RV Forums - View Single Post

Dave Gamble · 07-13-2019, 07:22 AM

Here's the story:

We have recently made two 5-day trips to a full service hookup. Everything worked fine, with the exception of another piece of my camper departing while on the highway (weather stripping around the front door, this time) with no indications of any kind of power problem. We unhook in the morning and are home within three hours.

I back the trailer in and plug in shore power. I use the tongue jack for the up-down-up ballet of detaching the load distribution and lifting from the hitch pin. I move the truck and hit the Auto Level button. I get a beep and an error that says LF JACK ERROR.

That cost me quite a few debugging hours before I realized that's just Ground Control's way of saying Low Voltage.

This, by the way, was mysterious in its own way: even if the battery was nearly dead (which I determined later when trying to use the tongue jack again), shouldn't the shore power have been enough? Or would it somehow opt to send some or all of it to the battery? I think the Ground Control is pretty thirsty - it doesn't like low voltage. It's kind cowardly to blame it on the left front jack, but there ya go. I was a coder - sometimes all you can show a user is your best guess as to what went wrong.

I should also point out that it takes a surprising amount of force to manually raise or lower the gear, even with a breaker bar. This is important to know because once the Ground Control gets in that fail mode, the only way that I have found to clear it is to manually lower and raise each leg.

So, this all called the health of the converter into question - maybe we had been living off of battery power for those 5 days, not the converter. That wouldn't have been much drain, but it would have likely been enough to weaken the battery enough to not be able to run the jacks.

The converter is very easy to get at in the 26RBS, so I checked its fuses and both were fine.

To check both the converter output and the applicable wiring, I disconnected the battery and tested for voltage at the battery cables. I also detached the umbilical to the truck. I had 13.7 VDC.

Today I hooked the cable to the trailer and disconnected shore power. I again had 13.7 VDC.

At this point I'm entertaining buying a new and better-suited battery and seeing how it goes.

07-13-2019, 07:22 AM	#9
Dave Gamble Member Join Date: Oct 2018 Location: Grove City Posts: 40	Here's the story: We have recently made two 5-day trips to a full service hookup. Everything worked fine, with the exception of another piece of my camper departing while on the highway (weather stripping around the front door, this time) with no indications of any kind of power problem. We unhook in the morning and are home within three hours. I back the trailer in and plug in shore power. I use the tongue jack for the up-down-up ballet of detaching the load distribution and lifting from the hitch pin. I move the truck and hit the Auto Level button. I get a beep and an error that says LF JACK ERROR. That cost me quite a few debugging hours before I realized that's just Ground Control's way of saying Low Voltage. This, by the way, was mysterious in its own way: even if the battery was nearly dead (which I determined later when trying to use the tongue jack again), shouldn't the shore power have been enough? Or would it somehow opt to send some or all of it to the battery? I think the Ground Control is pretty thirsty - it doesn't like low voltage. It's kind cowardly to blame it on the left front jack, but there ya go. I was a coder - sometimes all you can show a user is your best guess as to what went wrong. I should also point out that it takes a surprising amount of force to manually raise or lower the gear, even with a breaker bar. This is important to know because once the Ground Control gets in that fail mode, the only way that I have found to clear it is to manually lower and raise each leg. So, this all called the health of the converter into question - maybe we had been living off of battery power for those 5 days, not the converter. That wouldn't have been much drain, but it would have likely been enough to weaken the battery enough to not be able to run the jacks. The converter is very easy to get at in the 26RBS, so I checked its fuses and both were fine. To check both the converter output and the applicable wiring, I disconnected the battery and tested for voltage at the battery cables. I also detached the umbilical to the truck. I had 13.7 VDC. Today I hooked the cable to the trailer and disconnected shore power. I again had 13.7 VDC. At this point I'm entertaining buying a new and better-suited battery and seeing how it goes.