100 volts is too low.
yes, electric motors draw more current at low voltages
check the electrical connections between the power supply and the ac unit, ALL of them but especially within the ac itself
cleaning the ac properly is important too
somewhere in the system you are loosing voltage under high current load. check the voltage at several places starting with the shore power cord. check the voltage at other outlets while the ac is running, if all the outlets are showing low voltage then the main supply is poor. if its just on the ac circuit at the ac, then its the ac supply
check the connections where the shore power cord joins the trailer wiring, the flex line to the pedestal will be joined to solid copper wire in a box somewhere, mines under the dinette behind the hole where the flex cord enters the trailer, probably a couple of big Marr connectors in there
