spinners1 & ghsebldr,
The motors used are DC motors. I know there are various types of slides, so I'm not sure if what I know about mine might help or not.
Quite simply, my slide controller makes use of relays to change the polarity of + and - for extending/retracting the slide. One polarity extends the slide, the other retracts it. The rest of the wires are generally safety/control inputs. Such as: "engine must be running" or "engine must not be running", "parking brake must be set", "bay doors under slide must be closed", etc.
Also, if your slide motor has an electric brake as mine did, then when the slide motor is under power to extend/retract, 12V must be supplied to the brake unit to take off the brake.
Anyway, wiring up switches to extend/retract the slide wouldn't be that difficult, but you would be by-passing whatever safety inputs the manufacturer had implemented.
They really are NOT that complicated.
I had to install new relays onto my slide controller after about 3 or 4 years of ownership. If your unit isn't a potted assembly, you might wish to see if you can replace the relays on the board to see if that helps. When mine started acting up, I could usually get them to work by rapping the controller to setup a vibration. Often this allows the relay to kick in. In my opinion, the relays they used (at least on mine) are undersized in terms of their contact current rating, and I think the contacts pit fairly quickly.
Oh, the other thing is just to make sure that ALL grounds AND power connections at the controller(s) AND at the motors are clean and proper. Every volt counts at the motors to get things moving and dirty, corroded, burned or loose connections can keep things from working properly.
One of these days, I'm going to make either an Arduino equivalent controller or perhaps use one of the inexpensive PLCs that are available now. I think that project is about #397 on my "To Do" list. And that's not counting the list my wife has for me! LOL
Good Luck,
~Rick
ON EDIT: Just a thought....Spinners1, are the controllers the same for your front and rear slides? If so, temporarily, you could just use the good controller for both slides until you get the thing fixed properly. It would also confirm that the problem with the rear slide is with the controller and NOT wiring or motor related.
2005 Georgie Boy Cruise Master 3625 DS on a Workhorse W-22
Rick, Gail, 1 girl (27-Angel since 2008), 1 girl (22), 2 boys (23 & 20).
2001 Honda Odyssey, Demco Aluminator tow bar & tow plate, SMI Silent Partner brake controller.