Room slide out stops and starts

Check the 12 volt wiring at the HYd pump motor and make sure the cables are tight. Check the wiring from the Pump motor to its source both neg and Pos. Also, have someone operated the slides and take a 12 volt measurement AT the hyd motor and see if the voltage drops below 12 volts when running. Some Hyd and electric slides use a auto reset 12 volt breaker. If bad or loose connection they will trip and reset within a few seconds. If this has happened since new, they may have installed the wrong size breaker for the slide system. Doug

I did check the voltage, it is about 13.5v without running and runs just over 12v when the pump runs.

When the slides stop the voltage drops to 0v and then comes right back up and the slides start moving again.

Any recommendations on what I can try next to isolate this problem?

Locate the DC Circuit Breaker on POS wire coming from battery that goes to slides

It will be close to battery.
It is an auto reset....trips/resets
Bad connections (2 studs.power in/power out)
Undersized.

Don't see anything that looks like a breaker/fuse between the battery and the pump.

The positive cable runs to some studs before going to the battery, but this is where other wires are split off from as well (landing gear etc). The wires are just bolted together. The negative wire goes up into the trailer.

Within the trailer there is an automotive 20A fuse (not self resetting) listed as Slide, although this is likely for the outlets/lights but this fuse is fine.

Look on the negative side,.....it may run thru safety switches before going to the pump.
But maybe not on a trailer.

To clarify, I bought this trailer in 2008 and only this summer the problem started.

It is possible the breaker is undersized, but would expect that we would have had a problem before.

dbischops wrote:
To clarify, I bought this trailer in 2008 and only this summer the problem started.

It is possible the breaker is undersized, but would expect that we would have had a problem before.

Thanks for clarifying, thought Year we 2018 at first.

Breakers can get "tired" and trip at lower than their original rating.

Really sounds like a connection/terminal/wiring/switch/breaker problem. Can you feel around to check for a hot connection once the breaker trips?

I wasn't able to locate the breaker or any hot spots.

I am going to bring it in to the shop for this issue, but was able to fix a bunch of other little things since the last trip, but going to give up on this one.

Thanks for everyone that tried to help!

This is a very common problem. The Montana Owners Club forum (free to join by the way) has lots of discussions on this topic. A Search on "self resetting breaker" will uncover a great deal of technical information. Basically the original CB gets "tired" over time and displays the symptoms you are seeing. Go to your local NAPA auto parts store and buy a new one for around $5 and change it yourself. It looks like this and is under one of the two red covers on the wall behind the batteries. Find the wire that goes to the pump and trace it back the CB. The CB looks like this very tired one.

I would never have recognized that as a breaker, I will take another look as I believe I know where it will be (think I might have 2) and try that before bringing it in for service.