Keep Blowing Trailer Reverse Fuse

[Brad Gravenhof]

So I have a 2011 Tahoe, and it has a trailer reverse fuse under the hood. Problem is I keep blowing this fuse from time to time. It seems like it will work fine for a couple trips, then the next time out it will blow the fuse when truck is put into reverse. I've replaced the 10 amp fuse it came with to a 20, and even 30 and it still blows. I guess my question is does anybody have a good way to isolate if the short is on the trailer or if there's a problem with the truck side/plug??? I'm assuming I have a short somewhere anyway....... TIA

[CatFan]

You are going to damage something with a larger fuse in there.

Just look around the tongue. The blue wire has probably gotten pinched in the actuator.

[fishnfireman]

Sure sounds like an intermittent short. Which are the worst kind to run down.
I would start on the trailer simply because your truck only does it while hooked up.
Start at the front and visually inspect as much of the blue wire as possible. Like CatFan says check the actuator area and the foldaway tongue (if applicable) those areas would be most suspect.
Then work your way back paying special attention to any place it goes through the frame.
Had a turn signal short once that was inside a tube frame trailer.

[jimsch]

Can you use an ohm meter to read which or if a wire is going to ground?

[dabassking]

I had the same problem. Ended up being a bad spot in the wire insulation inside the trailer frame. It was in a straight stretch of frame too, not at any of the lights where the wires come out of the frame. I couldn’t pull the wire out to inspect it either be it was bonded to the other trailer wires in the harness. I spliced in a jumper wire to go around the bad spot and it solved it.

Edit to add: I found the location of my short by hooking the truck and trailer up and jiggling wires inside the trailer at every access point I could find until I could make the fuse blow on command.

[fishnfireman]

Can you use an ohm meter to read which or if a wire is going to ground?

Yes sir. so long as it's grounded at the time of testing.

[CatFan]

Can you use an ohm meter to read which or if a wire is going to ground?

It’s the blue wire and it’s only a couple of feet long unless you have backup lights on the trailer.

[Brad Gravenhof]

Thanks everybody.
I do have trailer back up lights, so I'm assuming the problem must be with one of the reverse lights on the trailer or the blue wire up front right?

[CatFan]

Thanks everybody.
I do have trailer back up lights, so I'm assuming the problem must be with one of the reverse lights on the trailer or the blue wire up front right?

All the same circuit.

[blkfalc4]

Yes sir. so long as it's grounded at the time of testing.

Not necessarily true, the backup solenoid (coil) could show up as a very low impedance to ground.

[bpicinc]

Put a new wiring harness on the trailer, problem solved and go back to q 10 amp fuse. Use shrink tubing on the wire and solder the connections.

[Bill Reynolds]

You don’t mention what trailer you have but I had the same problem with my Ranger trailer. Drove me crazy but I finally found it.
The wiring insulation was worn through on the outside wire by (I guess) blowing around in the wind when driving down the road. As it happens, the outside wire is the blue one if you have backup lights, and mine were worn to some degree at every washer and several were completely worn through. Easy fix though.
Really weird, but thought it would be worthwhile to pass on.

[billnorman1]

You don’t mention what trailer you have but I had the same problem with my Ranger trailer. Drove me crazy but I finally found it.
The wiring insulation was worn through on the outside wire by (I guess) blowing around in the wind when driving down the road. As it happens, the outside wire is the blue one if you have backup lights, and mine were worn to some degree at every washer and several were completely worn through. Easy fix though.
Really weird, but thought it would be worthwhile to pass on.

Looks like Ranger welded washers to act as cable guides but didn't treat them as a bulkhead and didn't use grommets. Worked for a while until Nature took its course and shorted the wires.
Anyhow find the blue or purple wire going to the reverse solenoid. Find out where it branches from the solenoid to the back up lights, and cut the wire to the lights in a place you can easily splice it back together. Put the correct fuse back in. If it doesn't blow after a trip or two you pretty well know where your issue is.

[Brad Gravenhof]

Ya, forgot to mention it's an 03 Easy Loader Trailer under a Skeeter. Tube style so who knows what's going on inside there. I'll go back and recheck everything I can see, and if all else fails I guess rewire. Thanks again for all the recommendations.

[MikeF]

Ya, forgot to mention it's an 03 Easy Loader Trailer under a Skeeter. Tube style so who knows what's going on inside there. I'll go back and recheck everything I can see, and if all else fails I guess rewire.

03 eh.

Just rewire everything and be done with it.

Every connection and every inch of wire (wear through) is suspect at that age.

Good Luck

ps.. Do yourself a favor and run a white ground wire down each tube and skip any frame grounds.

[fishnfireman]

03 eh.

Just rewire everything and be done with it.

Every connection and every inch of wire (wear through) is suspect at that age.

Good Luck

ps.. Do yourself a favor and run a white ground wire down each tube and skip any frame grounds.

[Bullet[BS]]

You can run a new blue wire all the way back near the back up lights. I had to get a cheap wire fish from Harbor Freight to run my new wire down inside the frame, make sure you use butt connectors with heat shrink on them to keep water out of the new connection. Never ever put in bigger fuses if you have a short you cause so much damage and could start a fire!!