I'm the one who started this thread, and it has been a good one, at least I've learned a few things. My Outfitter Apex 12.5 may be a 2004 model year - I bought it used. I did not like the noisy fan in the power controller that was in it. The power controller in it now is a (WF8735/8740) and since it is not old I discounted that as being a problem. I like it because it is much quieter than the previous one.
We found a melted fuse holder or fusible link in the battery box, connected directly to the positive terminal, so this may explain why the batteries were not charging properly. This was replaced with a new holder and 30 amp fuse.
As posted previously, the problems with the quirky rear camper lights (brake, turn signals) were solved by removing the rear light fixtures, cleaning the grounding points and making sure there was shiny metal to metal contact. Bad
grounding is not unexpected with a 10+ year old truck/camper.
My truck does not have a battery isolator, and I still want to get that in.
On to the troubleshooting: It made sense to start at the truck harness, move thru the cable connecting the truck to the camper, and then on to the camper batteries and power controller. It is possible, though you need to be a
contortionist, to access the outside cable plug thru the sliding door underneath the sink. The inside plug requires removal of the 'step' up to the bed. No obvious problems, corrosion, broken wires, etc. were found anywhere.
With the engine running we measure 14v at the GM harness, and 14 v where the cable connecting the camper passes thru, but 12 v at the camper batteries. A specific problem has not been found, but an additional ground wire was installed from the passthru to the truck frame. Over the next half hour the measured voltage at the camper batteries gradually climbed, though not reaching 14v..
So back to the controller box: I appreciate it that pilot996 took the time to post the schematic that he had drawn and it appears to be the same model of WF controller as I have, but I've found significant differences in wiring between my Apex and the schematic, as listed below. The controller has 6 x 15 amp fuses, each terminal color coded, and 6 wires coming out of the back of the box, color coded in the same way. Two of those wires are not connected to anything, leaving 4 to figure out which appliances they supply power to.
Measuring the voltage across the fuse holder terminals I find:
Fuse 1, brown, measures 0 volts, yet if I pull this fuse, water pump goes dead, panel with batt/water/gray/black goes dead, water heater switch goes dead, counter lights on drivers side go dead, roof fan goes dead, the furnace fan is dead. How can this be?
The printed circuit board onto which these fuse holders are mounted has a tiny, red, LED next to each fuse. This LED does not come if I pull fuse 1, but does when I pull fuses 3-6.
Fuse 2, gray, measures 0 volts (not connected to anything)
Fuse 3, blue, measures 12 volts - powers the overhead lights on the passengers side and the propane detector.
Fuse 4, yellow, measures 3 volts - powers the radio and perhaps the refrigerator.
Fuse 5, green, measures 0 volts (not connected to anything)
Fuse 6, red, measures 12 volts - powers the 12v plug for the TV - AND the the overhead lights on the passengers side go out when I pull the fuse! How can this be? See fuse 3 above.
The power to start the on-board Onan generator comes from somewhere else, as it cranks regardless of fuses 1-6.
So with some new fuses and cleaned grounds, most everything is operating again, but I don't know enough to interpret what seems to me to be the observations listed above. It seems peculiar to wire so many appliances to run off fuse 1, rather than distributing the load across other circuits. And before I forget what I've learned, I should draw a schematic.
Tom McCloud
2006 GMC 2500HD 6.6 diesel
2003 Outfitter Apex 9.5