20 Amp Interior Light Fuse Blowing When Putting Slide Out

[Rwgrigg]

My 2013 Heritage Glen 298RE TT blows the 20 amp fuse every time I extend one of the slides. The fuse powers some of the interior lights that are mounted in two of the three slides. All other 12vdc devices look OK. I don't see any obvious wiring problems. Is there any way to get a wiring schematic for the TT so I can trouble shoot the problem? The fuse is an automotive blade type.

[5picker]

Blown fuses can happen because of short circuits or an overload of the circuit.

Is your slide binding or straining? Have you regularly lubed the slide mechanism and treated the seals?

Have you put a DC amp clamp on the motor circuit and measured the current draw?

[Rwgrigg]

The slides work OK. It's just the lights. The fuse doesn't affect the slides. I suspect a 12v wire has gotten cut enough to short to the chassis (gnd) somewhere. I just don't know where to start looking without a schematic. I could use my VOM to start tracing the circuit if I had a drawing. Some of the wiring is inaccessible. I haven't put the amp meter clamp on the motor yet. (From a D28 picker!)

[5picker]

Ok, thanks for the clarification, I misunderstood and thought the slide stopped too.

Wiring diagrams are pretty much nonexistent for everything but some of the newer motorized units. The manufacturer just didn't use them or make them available.

Most of the lighting wiring extends/retracts via a scissors or coiled wire. (think old phone cord) Start looking at bend points or possible pinch points as the slide extends/retracts.

Keep on pickin'!

[Rwgrigg]

I'll have to get under the trailer and start tracing wires. Hopefully it's something I can get to. Thanks for the help.

[TSman]

If it is on dinette slide, try looking under the seats and drawers. I have a lot of wires moving around under mine including the wire for the lights on the slide. Does not take much to short it out.

[Big Vic]

I had the same problem. Only the light fixtures in the slide were affected. I got underneath the trailer and opened part of the protective undercover and found a 3 wire (+,- and ground) that had been pinched by the slide movement somewhere and was almost totally severed. The wire was designed to move with the slide, but somehow it got caught and was damaged. Repaired the wire and secured it a bit better so pinching was less likely.

[GFD47]

Agree with Big Vic. Since it happens when the slides are moving it's probably a short caused by the movement itself. Look for a bare wire along the slide out supports before looking anywhere else.
Also. in my experience wiring diagrams show only the schematic of the circuitry, and do not give any clues as to how the wires are actually routed, so searching for a wiring diagram is unlikely to help. You already know its the lighting circuit that's being affected.
Good luck!

[Tom48]

Originally Posted by Rwgrigg

I'll have to get under the trailer and start tracing wires. Hopefully it's something I can get to. Thanks for the help.

Start looking at what moves when the slide moves. On one of my slides it's a whole wiring and plumbing harness that slides back and forth through a slot under the refrigerator. For my big slide it's cable of wires paralleling the slide rail mostly protected in a conduit. In that kind of a case I'd look at the point where the wiring is entering the conduit and assume that something is flexing or bending. Does it happen going in and going out or just one way. That might tell you something too

[Rwgrigg]

Thanks guys. It's got to be the slides "catching" a wire somewhere. Will get under the TT and see if I can find the problem. Will probably be something simple----as it always is!! Will look into putting some protection on all of the loose wires that I can get to. Will reroute what I can and use good tie wraps to keep the cables away from anything that will "grab" them. Also wonder why they put a 20 amp fuse on a few interior lights----plus I just changed all of them to LED's!!