I'm working on a friends 04 S. It is blowing backup light fuses,5A. I have the back up switch out if I put a good fuse in it I get 12v at the switch. So i plunged in the switch and as soon as I press the switch it blows the fuse. I disconnected the back up light assembly from the plug in the rear, still blows the fuse when I depress the revers light switch. The wire that goes from the switch where it meets the rest of the wiring harness has a zip tie that looks very tight. I am going to cut the housing from around the wire and see if there is a short at the zip tie. Does anyone have any other suggestions? HELP is needed. Thanks!
I think you're on the right track. It's most likely a short between the switch and the lamp, somewhere.
Not certain this would be useful but here's the W10/W11 rear circuit diagram_WIRING. Look bottom right corner for the back-up circuit.
Thanks for the diagram. So I checked the ohms at the rear light connector. The meter when to 0. So i checked at the front plug that plugs in to the revers light switch and it stayed at one. So the short must be at the back half of the harness. How do you unplug the big round connector under the hood on the left side. I am thinking if I unplug it I will know if the short is under the hood or not. I hate this kind of problem.
You just grab the two halves of it (one in each hand) and twist counter-clockwise. And it will open up. If it's never been done before, they can be stuck pretty good.
Ok I gave the car back to my friend in defeat!! I could not find the problem but I told them that when they bring me the car gain I will look agin. Here is what I did. Replaced brake switch....fuse blew Connected old switch held it in my hand and pressed......fuse blew. disconnected the back up light assembly from plug and did above with the switch......fuse Blew. put ohm meter on the yellow and blue wire at the rear of the car it showed a ground(went to 0) the same wire at the switch same results. Disconnected the plug on the driver side under the hood now at the switch it does not ground, tested it at the plug and it goes to ground 0 ohms. I checked the same points on my car and the meter showed 1.5 something. I told them I did not want to start pulling interior panels off the car with out a more clear plan. Every thing works on the car just the back up lights. They are going to live with it for now and like I said I will try agin later. Does anyone have a clue what I could try next time?
If the light wants to go around blowing fuses, thats really none of my business... Who are any of us to say who and what the light gets freaky with or not.