Why doesn't my back-up light work?
 

I'm having trouble with the back-up light in the '02. It hasn't worked for a while, so I thought I'd change the bulb this weekend. Put in a new bulb.... no light. Tried the other bulb that came in the package.... no good either.

Checked the socket with my voltmeter...11.8V (engine off; battery voltage is 12.4). Disconnected the socket from the wiring harness, adjusted the tabs inside, put a bulb in it, and there's continuity across the pins, so the bulb has a good connection. Hook it up again, still no light.

Checked the voltage across the wires with the bulb installed, and I only see 0.5V.

Does this sound like the switch is bad (and unable to supply enough current to illuminate the bulb)? Or something else? Any ideas?

I had the same problem, and this thread helped me to replace the switch myself. I think the part was around $20 or so.

I was thinking about the reverse light switch also, but if that is the case, why would there be voltage at the light socket? I don't think I measured the voltage when my switch died. I simply replaced it.

That's why I'm so puzzled by this.

Maybe the switch is on the ground side of the loop?

The voltage I measured earlier was between the two wires going to the lamp socket. I just went out and checked, and it has a switched positive & constant ground. The ground wire is good - I put the lamp between it and the battery and it lit right up.

I don't recall the exact configuration of the reverse lamp, but some other bulbs are in replaceable sockets. I've had trouble with some marker light sockets that get water in them and corrode. The lamp socket detaches easily from the wiring socket and is cheap. I've had to replace a few over the years. Just did one yesterday.

Well, I finally got around to installing the replacement switch, and that took care of it. The switch that came out was full of oil, like the one mentioned in the other thread. $13 for the switch from Classic, and 5 minutes to change it...not too bad.

Does anyone know where to buy the reverse light switch for the Mini Cooper S 2002 R53 online? Or is the dealership the only option? Anyone know the part number?

According to realoem.com, the part number is 23117527716. I bought mine from Classic MINI, my local dealer which happens to offer discounts to NAM members. I think it was around $13 with tax, because I picked it up at their parts counter, but they ship parts too. Their phone number is 440-585-9910. They have an email address too, but they don't always respond.