Possibly a bit different approach to how you move the slides and how you get power to them will help?
Two things may be in play here, so a couple points. One is that all motors work better and last longer if they get good solid power. when the power may be a bit low, that creates more heat in motors and that heat can be fatal over time as they "burn out" when the insulation on the motor winding gets too warm too often.
When we have the RV engine running the engine alternator connected to the chassis battery is also connected to the coach batteries. That makes a whole chain of those three things all available to move slides, jacks, or any high power items that need it!
So it is always a good idea to assure the best operation by starting the engine first!
When you mention the slide moves again when you hit the boost switch? That is a good indication that the first battery is not giving quite enough power and you are tying in the second battery group when you hit the boost!
Far better to just start with the engine running and not push the motors to try to work with less than really good power!
But that is step one and there may be a small point missed on moving the slide? There are two motors and that means one will be slightly slower than the other in most cases. Motors that we try to build exactly alike will rarely move exactly the same as each will have different stresses or loads on them.
The motors in slides are made with a bit of "slack" built in to allow us to let the slow one catch up if we hold the switch for a bit after it appears the slide is fully out or in!
Some call it syncing the motors?
I call it letting them get their act together and it's a good practice to just be a little bit slow on releasing the switch when moving the slide.
five seconds maybe? Not like 5 minutes where things could heat too much!
Hope that makes sense as there can be other things going on but this is a frequent thing to find. The problem is we can't watch each other to spot any small points on how we work!
See if that helps and shout back how it goes!
