Forum Discussion

gb76087's avatar
gb76087
Explorer
Mar 28, 2021

Aux Start to Boost Cranking Amps

2007 Fleetwood Terra, F53 chassis.
The coach has Power Gear electric leveling system which requires a very healthy chassis battery. If the chassis battery is weak, the jacks don't work.
My question is if the chassis battery is weak could I hold the auxiliary start switch(the engine is running) and retract or extend the jacks at the same time?
Class A

16 Replies

Show More
  • Bruce_Brown's avatar
    Bruce_Brown
    Moderator
    Mar 28, 2021
    chuckftboy wrote:
    That's confusing. You said if the engine is running and if it is, the alternator should be suppling the power for the levelers. The alternator should be able to supply all the power needed.
    To answer your question...yes you can use the boost switch with the engine running.


    This. When our jacks show low voltage all I need to do is start the MH and it's good to go.
  • DrewE's avatar
    DrewE
    Explorer II
    Mar 28, 2021
    I agree with everyone--yes, it is okay to do that.

    However, there's a pretty good chance that pressing the button isn't actually doing anything with the engine running, since a very common setup is to use the aux start solenoid as the battery combiner/isolator relay and have it engaged whenever the engine is running.
  • gb76087's avatar
    gb76087
    Explorer
    Mar 28, 2021
    From experience, if the battery is not up to snuff, the jacks can go into error mode. Theoretically I agree with you, but not what I've experienced.
  • chuckftboy's avatar
    chuckftboy
    Explorer
    Mar 28, 2021
    That's confusing. You said if the engine is running and if it is, the alternator should be suppling the power for the levelers. The alternator should be able to supply all the power needed.
    To answer your question...yes you can use the boost switch with the engine running.

About Motorhome Group

38,738 PostsLatest Activity: Jul 26, 2025