Citroen XM Forum

I have a strange issue with the reversing lights. They like to stay on all the time.
I have rewired them from the inhibitor switch, to match the manual set up. But still they remain on when the ignition is on.

Has anyone ever experienced a failed switch on the gearbox and got these symptoms? It's the only thing I can think of that's wrong.

Switch on gearbox failed here last year - went intermittent after 21 years.
End of its plunger was worn away.

It's a simple 'make' switch when reverse is engaged. If you unplug its 2-pin connector and the rev lights go out, then the switch is either stuck or duff. You can unscrew it and check it off the car. An almost universal part across good few PSA cars, iirc.

Original switch was 2257 40 (2.1, 2.5, 3.0), now NFP.
Mister Auto has the part: FAE 40570 Reverse Switch £4.70.
Fitted this to the 2.5; identical to the original.

Exception is that 2257 41 was fitted to the BE3 box on 2.0, and still shows as available.

Thanks Chris.
I went out and bought a new one this afternoon from GSF. It is a simple switch, I understand how that works now.
I reckon mine has got stuck on. Typically everything is back together and access is now awful. Still I shall try and get that replaced. It has to be that, as there is nothing else it can be. Having poured over and rechecked the wiring mod, it can't be anything else.

Access on the 2.5 was pretty awful too - all pipework and battery boxes in the way! Most was done by feel, rather than ever getting a good view.
Are you driveable now?

Not quite Chris. It's been started many times, but I haven't driven it yet. I need to bleed the brakes as I had to replace a front calipar. It started to weep LHM over the winter. Opening it up it was a sea of water and rust. And possibly disturbing the LHM tank again for the switch I thought just leave it sitting for now until the reversing lights and brakes are done.

I have got to the switch on the gearbox withought unplugging the hydraulics, but I'm waiting for a 20mm long reach socket. I don't have any long reach sockets. Shameful!!
Once again, a simple enough job taking four days!

I think I used a ring spanner on the switch here; similar top position, but a different 'box.

Well I'm totally baffled. I have replaced the switch. I have cut every damned wire off the inhibitor switch plug, incase there are any looped wires throwing things off. According to the wiring diagrams wires 8&9 are the reversing light wires. They are hooked up to the switch on the gearbox.
I have even tried swapping them round and the lights are still on all the time no matter what. Putting it into reverse doesn't do anything. I don't get it!

What happens if you pull the connector off your (new) gearbox switch, so the switch isn't in circuit? Do the rev lights then go out?

That is a good point Chris. Not tried that. Drat... obvious one that one.

Thanks.. will report back.

Right, I'm convinced this car is possessed!

I have unplugged the connector. The lights stay on.
I have taken off each wire in turn at the connector, and they still remain on.
I have removed both wires from the connector and so they are now not connected to anything. The lights are still on.
Somehow they are being powered, but how on earth, I don't know.

Totally confused now!