No reverse lights

[chrisandmark]

Hi,no power going to reverse light,found reverse switch on gearbox,took switch cover off,bridged terminals but blows fuse.put a bulb on and it lights up,terminals clean on back lights all other lights work,any advice appreciated..

[loot]

F33 is the reverse lamp fuse at the engine fusebox it goes through the reverse lamp switch to the bcm logic and pass through and it then goes to both rear reverse lamps.

The switch is a bridge so if you bridge the pins then it shouldn't blow the fuse. A lamp will illuminate though in either scenario.

You need to continuity test the reverse lamp switch to check it and then you need to disconnect the rear lights cluster connectors and make sure that the pins aren't shorting at the connectors, once that is fine you can bridge the reverse pins and it shouldn't blow the fuse or if the switch works you can now leave it in reverse and if it doesn't blow the fuse then you know that the wiring is correct until the cluster connectors, refitting the clusters again might blow the fuse but that will be the problem and easily fixed. If however the fuse blows with the clusters disconnected earlier on in the checks then there's a short somewhere or the bcm is toast

[chrisandmark]

What's the bcm

[knobby1]

What's the bcm

Body Control Module.

Lord Knobrot

[chrisandmark]

Hi, I've tested the switch on a multimeter and we've got continuity so what's the next step please? Thanks

[loot]

Unplug both back lights connectors.
Brushes pins again to see if it blows the fuse. Let us know the answer.

[chrisandmark]

I'll go and try that now. Thanks

[chrisandmark]

Bridged connector, sparked but didn't blow fuse this time.

[chrisandmark]

Just realised it wasnt in reverse when bridging connector!

[loot]

If the switch is disconnected it doesn't matter

[chrisandmark]

What's the next step!

[loot]

Right so, with lights connected and you unplug the reverse connector and you bridge the 2 pins in the connector not the switch, the fuse blows yes?
If you unplug the lights and bridge again it doesn't blow?

Confirm if that is correct.
Next is clean the pins on 1 of the light clusters, scrape any rust off and from each pin it goes to the bulb, make sure that pin track is clear. Also check the bulbs are correct because some ppl have been known to fit twin or single bulbs into the incorrect socket which can cause a short. So all lights should be single filament except stop and tail.

So when the cluster is checked and good fit it to the connector and bridge the switch connector again. The reverse bulb should light up. Ignition on.

If it works repeat with the other side cluster ok.

[chrisandmark]

Yes that's right,but it still sparks when bridging connector,light clusters ok,have cleaned pins,also I wired cluster straight to a battery and all lights work ok.

[loot]

It will spark a bit but not blow the fuse.

So now what happens?

[chrisandmark]

I dont know!