Reversing light not working

[tomsimmons]

Morning All

I know this topic has been mentioned a couple of times on here, however...

My Girlfriend has a 51 plate Cooper, the reversing light has stopped working. I changed the bulb, still nothing. So after a bit of reading it seems the gearbox switch is a common culprit, so I've got a replacement switch to fit.

The problem is the previous thread state that it's under the air filter, looking at that the clips that hold the large pipes in place seem to need a special tool to remove them, what ahppened to good old jubilee clips?

One thread said that you could gain access by removing the arch liner, so while I was doing the brakes this weekend I had a look. I removed all the fixings for the front half of the liner and behind it was nothing of note. You can see a fair amount of the gear box around teh suspension, with the liner in place, but I couldn't see the switch.

Could some well provide me with a little more info on where the switch is, and how to access it please?


Thanks

Tom

[XRV848]

I think it's only on the Cooper S that you can access the reversing light switch through the wheel well.
You will need to take off the air filter box to get at yours, it's not too difficult, but does require a bit of fiddling. Don't worry about disconnecting the air hose. undo the screws that hold the air filter box top on. Move the lid towards the engine (necessary as there are two tabs on that side of the box that must be disengaged) then lift the lid and, with the hose connected, bend it back out of the way. Remove the airfilter. Undo the screws that hold the box in place and free the wiring clip on the bracket. Now is the fiddly bit. There are two pipes that go into the box, both are push fits. Remove the box while pushing, shoving and swearing until the two pipes are free. Save some swearing for trying to get them back on reassembly. The reversing light switch is then visible on top of the gearbox. Remove the connector, then the switch. Replace in reverse order.

[Silverado]

That big circular clip is a pain to refit but it didn't take too long. I was half expecting that I would have to buy a replacement jubilee clip.

It's not a difficult job to remove the air-box.

[tomsimmons]

OK, got the air filer out, was actually a piece of cake.

Discovered that my sockets are to shallow to go over the switch.

Decided to check the switch that was in there, open when not in reverse, closed when is, damnations the switch would appear to be OK then.

So I guess I'm looking at a wiring loom or bulb holder issue? Tomorrow I'll take the bulb holder out and check if there's any sign of voltage there, if not, you guys any idea where to start looking after that?


Tom

[Silverado]

Fuse F13 ( Reversing light - 5amp).

That's from the Haynes manual.

If not I'd carefully pull the 2-pin connector off the bulb holder and check for voltage with ignition on and car in reverse.

[tomsimmons]

Quote: Originally Posted by Silverado (original)

Fuse F13 ( Reversing light - 5amp).

That's from the Haynes manual.

If not I'd carefully pull the 2-pin connector off the bulb holder and check for voltage with ignition on and car in reverse.

OK, fuse is fine.

Took the lamp out again, checked the bulb again, actually put 12v across it to check, bulb is fine.

If I unplug the holder, and stick a meter in the plug, I can see 12v

If I stick the meter in the bulb holder when having reconnected, I see 12v, but thee bulb will not light!

I'm not idiot when it comes to this kind of thing, but I'm at a loss on this one, anyone got an idea?

I phoned BMW, they want £5 for the holder. Why can't someone have the decency to crash a mini so I can scavage the holder from the knackers yard?


Tom

[Silverado]

Try a different make of bulb or fiddle with the connectors on the holder.

In the end I bought a new holder for my 03 plate car. Cost was £3.54 mail order. Part number 63226916986.

[tomsimmons]

Quote: Originally Posted by Silverado (original)

Try a different make of bulb or fiddle with the connectors on the holder.

In the end I bought a new holder for my 03 plate car. Cost was £3.54 mail order. Part number 63226916986.

I take it you had the same problem?

Rip off merchants BMW wanted £5+ for a new holder!


Tom

[XRV848]

Did you just check the continuity through the switch with the meter? When my switch failed it was the same, showing open circuit then low resistance (but not zero ohms) when the gearbox was in reverse, but there was sufficient resistance there to prevent the light from working. I think the lamp is 15W, which means that it will draw about 1.25A. 5 Ohms resistance will mean that half the voltage is dropped across the switch.
Try measuring the voltage on the lamp side of the switch (with the car in reverse and the lamp in circuit) to see how many volts are being dropped across it. Volts between the input side of the switch and ground, about 12V, volts between the output side of the switch and ground should be about the same for the light to work.

[tomsimmons]

Well I'd given up and was looking for a replacement holder then watching the girlfriend leave for work the other day, bugger me if the damn thing isn't working!

I was getting a good change over on the switch, which yes what a continuity check. I had also spent time sat in the middle of the road with the meter getting her to put the car in reverse and back out and saw a good 0 to 12v and back again.

Anyway, it's working for now, all I need to do is get the airbag/belt warning light cleared and all will be fine. No nice generous soles in Aberdeen listening who have a reset tool they'd be willing to demonstrate on said car is there?


Tom