Rear Leveling Jacks pulling 119 Amps - 80 Amp CB does not reset

[ajg617]

Dealer said it was the cold weather keeping the rear jacks from retracting. GD said it was probably low battery voltage. Repeated the tests with my son today. Unit was level with all jacks down and temperature was 55F with 110V disconnected and both batteries reading 14.4V. I measured with a dedicated ammeter and also had the display from the Victron BMV-712 showing amps. While my son pressed the hitch height button and watched the jacks retract, I measured the draw which ran from an initial 60.1 Amps up to 119 Amps on both the ammeter (measuring between the pump and the 80 Amp circuit breaker) and the Victron as the four rear jacks retracted. The 80 Amp circuit breaker did not reset. We repeated the test and after re-leveling I measured amperage between the 80 Amp breaker and the batteries after hitch height button was pressed. Same results and brought the batteries down to 12.2V.

The two batteries are 100Ah Battleborn LiFePO4s installed last April and connected in parallel. With batteries again charged to 14.42V as measured separately I completely disconnected them from all electrical supply and draw and let them sit for one half hour. After that half hour, 13.39V and 14.41V.

With 110V disconnected and batteries again fully charged, the front jacks pulled a maximum of 70amps when lowering after hitting auto-level. The two off-door side jacks pulled a max of 45amps and the two door side jack a max of 40amps when lowering during the leveling process. It appears that the rear jack motors draw significantly higher amperage when retracting.

I don't understand why the 80 CB isn’t popping at 119 Amps? In colder weather, I hear it click and the jacks stop moving. 119 Amps seems a bit high? Just isn't adding up for me.

[Hoopy Frood]

Do all four rear jacks come up at the same time? Are these electric jacks, or hydraulic?

[ajg617]

Do all four rear jacks come up at the same time? Are these electric jacks, or hydraulic?

Howard,
They are hydraulic, so running off the same pump. The middle two start to retract first, then the rear two start retracting after the middle ones are off the ground. When all four are retracting, the Amperage starts to climb steadily. I really was stunned looking at two displays - my clamp meter and the BMV - both agreeing. The front two of six didn't extend to hitch height so I have to wonder what the load would be if all six were moving.

[Hoopy Frood]

That really sounds odd, mine pull about 65 amps when retracting the back four jacks for Hitch Height. Is it the same amps if you're connected to shore power? It does sound like low voltage is ramping up the amps as the other jacks are raising. But it really shouldn't be that much different raising 2 or 4, not like lowering and leveling. Basically no load when raising, or rather should be no load.

If you raise the two jacks on one side manually, does the motor load go up? Maybe you have one jack that is sticking and that's drawing the load?

[ajg617]

If you raise the two jacks on one side manually, does the motor load go up? Maybe you have one jack that is sticking and that's drawing the load?

Haven't tried retracting them manually but the auto-level lowers the two off-door side rear jacks first and that pulled 45 Amps. Then it lowers the door side rears and that pulled 40 Amps.

GD wanted me to make the measurements with no 110V connections. I'd say my readings were wrong but the two ammeters agreed and two cycles of hitch height and auto-level brought the batteries down to 12.2V which also was more of a drop than I expected. Isn't it just the one hydraulic pump and solenoids for each of the jacks?

[huntindog]

Dealer said it was the cold weather keeping the rear jacks from retracting. GD said it was probably low battery voltage. Repeated the tests with my son today. Unit was level with all jacks down and temperature was 55F with 110V disconnected and both batteries reading 14.4V. I measured with a dedicated ammeter and also had the display from the Victron BMV-712 showing amps. While my son pressed the hitch height button and watched the jacks retract, I measured the draw which ran from an initial 60.1 Amps up to 119 Amps on both the ammeter (measuring between the pump and the 80 Amp circuit breaker) and the Victron as the four rear jacks retracted. The 80 Amp circuit breaker did not reset. We repeated the test and after re-leveling I measured amperage between the 80 Amp breaker and the batteries after hitch height button was pressed. Same results and brought the batteries down to 12.2V.

The two batteries are 100Ah Battleborn LiFePO4s installed last April and connected in parallel. With batteries again charged to 14.42V as measured separately I completely disconnected them from all electrical supply and draw and let them sit for one half hour. After that half hour, 13.39V and 14.41V.

With 110V disconnected and batteries again fully charged, the front jacks pulled a maximum of 70amps when lowering after hitting auto-level. The two off-door side jacks pulled a max of 45amps and the two door side jack a max of 40amps when lowering during the leveling process. It appears that the rear jack motors draw significantly higher amperage when retracting.

I don't understand why the 80 CB isn’t popping at 119 Amps? In colder weather, I hear it click and the jacks stop moving. 119 Amps seems a bit high? Just isn't adding up for me.

13.39 and 14.42
Something is wrong there. Either the 13.39 one isn't getting charged, or it has a problem.That could cause a low voltage/higher amperagre situation with the jacks.

[ajg617]

13.39 and 14.42
Something is wrong there. Either the 13.39 one isn't getting charged, or it has a problem.That could cause a low voltage/higher amperagre situation with the jacks.

Good catch - but I think I mis-typed - 14.39 and 14.42V. I'll re-verify tomorrow. But 12.2V across both after no more than 15 minutes running the jacks seems a bit low.

[Hoopy Frood]

To the best of my knowledge, limited I admit, there is one pump. And one solenoid for each set of cylinders.

[Scott'n'Wendy]

First off, cold weather will increase amperage significantly. But....don't think that's your problem.
You have one pump.
IMO....and you know what they say about opinions....
The only thing that will cause the pump to increase draw is increased line pressure. Drawing 100+ amps retracting means pressure is high..but pressure should only spike once fully retracted. Not travelling to the retracted position. There is something wrong with either....the solenoid(s) for the rear jacks, the lines that allow fluid to get back to tank when raising, or the cylinders of the jacks themselves (unlikely with two doing the same thing).
I would also do the same tests with 120vac shore power connected. If amperage is significantly lower...could point to a battery problem. I don't think you have a battery problem, but get the data.
No pressure gauges on the system I'm thinking? Diagnosing hydraulics without pressure gauges is not easy. It's like diagnosing electrical without a meter.

[Scott'n'Wendy]

If you could contact GD and see if they would give you the hydraulic schematic it would help troubleshooting.