Disconnect the tow vehicle, at least until you have time to locate the problem. I suspect your house batteries are weak or connections have high resistance, causing the slide motor to draw amperage from the tow vehicle battery during the second (retract) motor activation.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"