964_UK

Hi Guys,

My Reverse Lights have never worked since owning this vehicle and yesterday I finally decided to investigate the issue, so armed with a Multimeter I got started.

I get no current through the reverse light wire when reverse is selected.

The Gearbox has just been exchanged and the switch was exchanged at the same time, so I doubt both switches would be at fault. Although, it could be!

What I think is the wire from the switch to the rear lights is broken at some point.

I want to run a new wire first.

Does anyone know how to go about doing this? Or has anyone attempted this before?

Thanks

Craig

Droops83

Craig,

Which wire did you check for power? There are 2 wires w/ bullet shaped plugs that plug into the reverse light switch. I'm at home right now so I only have the crappy Bentley wiring diagram as reference (I'll check the factory diagram at my shop if I have time/remember), but it says that the power comes from the green wire w/ yellow stripe, it is powered by fuse 11 and is hot with the ignition switched on. Turn the key on to the "run" position (2 clicks, engine does not have to be running) and see if there is power at this wire. If so, short it to the grey wire, which should be the other wire that plugs into the reverse light switch, and see if the reverse lights come on. So, if there is power at the green/yellow wire and the lights come on when shorted to the grey wire, you know the problem is either the reverse light switch itself, or a problem with the pin that activates the switch when the shifter is in reverse.

If there is no power at the green/yellow power wire, then the issue is upstream. Check fuse #11 and the fuse holder condition, and whether that fuse even gets power in the first place, and go from there. These cars are old now and may have had countless previous owners/mechanics messing w/ the wiring, and consequently things may not be wired as the were from the factory (stereo shop installers are the bane of my existence!!!!), so go around w/ a test light and see how far you have power . . . . .

If there is power at the green/yellow wire but the lights do not come on when the wires touch, then the issue is obviously downstream of the switch, and the continuity/condition of the wires/connectors/grounds need to be checked. Also on these cars it is common for the bulb sockets in the taillight housings to be corroded, or the spring loaded contact that provides power to the bulb is weak or broken (although this is uncommon when BOTH lights don't work as in your case, it is worth checking since it is so easy to do so).

Anyway hope this gives you a start, let us know how it goes.

---Chris A.

964_UK

Thanks for the reply mate,

The wires at the lights themselves = 3 in total, one for the Fogs, and one common, + an extra wire which wasn't wired up - This I assume is the Reverse Light wire.

Unfortunately the Wires are old and faded and every one of them looks a faded, murky white, seems all the colour has faded away.

I will be checking again soon, but as you may have heard it hasn't stopped raining in the UK for almost a month, and I have no garage!

Once weather clears I will get underneath the car and check the wires on the switch, I did recall checking the fuse visually but not with a meter. Will do that on your advice.

Did check the bulb holders and when wired to the fog light wire they come on happily.

I will let you know what happens.

Cheers

Craig