Lenp

Might want to check the voltage at the motor itself to make sure there isn't a bad connection someplace between the batteries and the motor. Check the voltage while the motor is running. I had a problem with my hydraulic slide on my last fiver that ended up being a loose connection at a solenoid that dropped the voltage to where the motor would not run under load. Lenp

Bill, He may not have had an invertor - my last fiver came with the Norcold 1210 with ice make but no inverter. Lenp

Many (most) RVs come from the factory wired so the frig DOES NOT run when on inverter power. When I replaced the original absorption refer with a household unit I actually installed a second 2000 watt pure sine invertor dedicated to the refer. Lenp

When you say "power is good coming in" have you actually measured it? IF the voltage is low or high the SurgGuard will not allow it to pass into the coach. likewise, if the pedestal is wired incorrectly it may block power. As noted above, check your power cord. I had a 50 amp cord loose the ground connection and my SurgGuard would not let power pass. Good luck! Lenp

The fact your GFCI is popping when #2 heating element is connected suggests the element (or wires) may be contacting something it shouldn't. And, yes, if replacing one, replace both. Lenp

I had a 2011 which I think is basically the same as your 2010 and it was not WAS NOT flat towable so I traded for a 2012 which is very easy to place the transfer case in neutral. Lenp

When you say the voltage drop across the motor is .2 volts does that mean your reading is taken with one meter lead on the positive side of the motor and the other lead on the other side of the motor? If that is the case you should read 12 volts not .2 volts. And if that is how your reading the .2 volts I think you have a bad connection on negative wiring. Lenp

When checking the voltage I suggest you measure ACROSS the pump terminals to make sure you don''t have a bad ground connection somewhere. If your measuring from chassis ground or negative battery terminal to the hot terminal you could be getting a false reading of what is actually across the motor. Lenp

Sounds to me like insufficient voltage issue. Check the voltage ACROSS the pump (assuming hydraulic operated) or motor if electric. Could be a bad ground connection. Lenp

My son had his trailer stored at a fenced (secure?) storage facility and some broke the entry door lock and actually lived it the trailer for a week before it was discovered. No hookups but the toilet was used and FULL of "stuff". What a mess. Took a lawsuit to get the storage company to cover damages. Lenp

Same refrigerator in my coach and the frig part defrost failed. Using the Samsung schematics I was able to locate the defrost heater leads in the rear of the unit and found I had an open circuit. Ended up being the thermal fuse located near the heating element. Cheap part but a pain to replace. I now carry a spare. Contrary to what Samsung told you, I was tole NOT to run it on a modified sine invertor. Guest it's all in who you talk to. Regardless, I am using a pure sine and still blew the thermal fuse so maybe it really doesn't care. Yours being both freezer and frig probably a different issue. Lenp

Keep in mind the exhaust brake works better at higher RPM. Thus, the lower the gear you can safely get to the better the braking. Lenp

Mine may not be the same but I was able to remove the outside vent and pull the hose outside a little and reconnect it to the vent and slide it all back in again. Lenp

Wiring to the 12 volt receptacle is probably 12 or 14 gauge wire. When the compressor tried to run the voltage drop is too high. Try running a new circuit direct from the batteries (with a fuse in line) using minimum of 10 gauge wire for both ground and 12 volts. Lenp

Measure the voltage with everything connected if you can. Perhaps across the bulb(s) themselves. Measuring 12 volts (or 13 or ??) at the connector without the lights connected is meaningless. A high resistance connection (or ground) will still pass the full voltage when no current is being drawn. I like to use a 12 volt trouble light to probe the wires https://www.amazon.com/Voltage-Continuity-Current-Tester-Indicator/dp/B01BGZ9XRS/ref=sr_1_5?keywords=12+volt+trouble+light&qid=1572750908&sr=8-5 Try it across the battery first to get an idea of how bright it should be. If there is a bad connection somewhere the light will be dim. If you use one of these be sure to connect the ground clip to the ground lead in the plug to verify it is tied to a good ground. Lenp