No Reverse Light

[Luke 7 1 Cars]

I've read through a lot of old threads to get my reverse light working but I've hit a bit of a wall!

 

I got the old multimeter out and did some testing:

 

I have a phase 2 with the reversing light on the bottom valance.

 

The bulb is fine and the cabling from the passenger light cluster to the reversing light is fine. I tested by rewiring the brown loom so the revering light was powered from the fog light feed (swapped the red and orange cable over) and the bulb worked as it should.

 

As far as I can tell the is no voltage in the red cable in the brown loom at the back of the passenger light cluster.

 

The fuse is in tact and the other things running off fuse 1 (fuel gauge etc.) work fine.

 

From the wiring diagrams the problem must be between the fuse and the brown loom but I don't know where to look. From old threads people have said check the switch on the gearbox but I have not idea how to access that!

 

Any help would be much appreciated.

 

Cheers

Luke

[Slo 283 1 Cars]

If you look down the side of your battery (might have to move the air box pipes out the way), you will see the clutch release arm. The reverse light switch is directly underneath it in a recess and usually has a black connector with a brown and purple wire.

[Luke 7 1 Cars]

Thanks will get the multimeter on that when I get back tonight!

 

Thanks for the quick response.

[Tom Fenton 1,542]

Easiest check is, pull the plug off the switch, short across the wires with a short test wire. If the reverse light then comes on then everything else is OK and your problem lies with the switch. Easy enough to change the switch, just undo with a socket and fit a new one.

[jackherer 543]

Just unplug the switch and short the two pins on the plug with a bit of wire.

 

edit: too slow!

Edited April 11, 2014 by jackherer

[welshpug 1,657]

Don't forget to turn the ignition on, I remember someone doing that

[Luke 7 1 Cars]

I have a feeling the switch is OK because when I got the car it worked as it should but would still work when the ignition was off. Which left me with a few dead batteries when leaving it in reverse on a hill.

 

It was bodged to work with the earth wired from the reverse light on the valance through a hole in the boot floor to the live side of the boot light. (no idea how that worked!)

[Slo 283 1 Cars]

Hmm the only live should be directly to the switch, live then switching from the switch to the tail light? If it was bodged with a live from the rear of the car it could possibly have burnt out the contacts in the switch. I had permanently on reverse lights once, why will always be a mystery to me but it resulted in a fried switch.

[Luke 7 1 Cars]

Ill check the switch when I get home tonight.

 

Thanks for your help.

[Luke 7 1 Cars]

I'm not good with engines. I can't find this switch for the life of me!

[welshpug 1,657]

Its not on the engine!!

 

Look at the clutch arm from above, near that will be a two wire switch screwed into the gearbox.

[Tom Fenton 1,542]

I have just taken a picture. To be fair on a car in standard form you cannot easily see the reverse switch. In the photo I am looking leaning over the passenger wing. The battery you can make out. My LED torch is pointing straight at the switch. You would have to move some stuff out the way to get at it. Intake hose probably would be a good start.

[Luke 7 1 Cars]

That's for the pic. I found it. God knows what's been done to it before! I will post a pic later.

[jackherer 543]

Early and late cars used a different plug for that switch so if its been messed with it might have had a different gearbox put in at some point.

[Luke 7 1 Cars]

OK, another thing ruled out!

 

There was a mess of cables down by the switch. I've rewired them properly. I did a continuity test across the switch and its working fine (0 amps when in reverse and 1 when not in reverse)

 

But the red and purple wires at the gearbox are still reading 0 volts. The ignition is on and the fuse is still in tact.

 

What shall I check next? Can't be much left to check!

[jackherer 543]

The reverse light wires go to a brown multiplug which is probably the mess of wires you found. From there they then go into the cabin so the next place you need to look is under the dash from the drivers footwell. If you can find where the wiring loom comes through the bulkhead and follow it back you'll find two more brown multiplugs, the reverse light wires should be pins 1 and 2 on the larger plug (wires 52 and 53). Check for voltage there and if you find it is live the problem must be somewhere in the wiring between the two multiplugs.

[Luke 7 1 Cars]

Still no live at the brown multiplug in the cabin.

[jackherer 543]

I'd re-check the fuse next, make sure it actually conducts current even if it looks OK and also check for voltage at the fuse terminals.

 

It's hard to suggest anything specific other than that given the bodges you described, who knows what has been done to it. You're going to have to get your head around the wiring diagrams in the back of the Haynes manual and check everything is how it should be.

[Luke 7 1 Cars]

It's working! (well with the fog lamp holder for now)

 

It was easier to figure it out once I realised there was only power to fuse 1 once the immobiliser was disengaged! ​ It was wired completely backwards with the live coming from the boot light and earthed in the engine bay. Now its just the lamp holder that needs replacing.

 

Thanks for your help everyone!

[Luke 7 1 Cars]

Also, I unplugged something in my hunt for the reverse switch and cant remember which way around it goes. Can anyone tell me which way round this plug should be wired? (or if it matters)

 

[Slo 283 1 Cars]

You might as well have a picture of a wheel nut lol what does that plug go to?

[Luke 7 1 Cars]

Haha good point. It's one of about 3 plugs on the back of the gear box

[Luke 7 1 Cars]

I think it's the gearbox! Back right of the engine bay underneath the dizzy cap.

[Slo 283 1 Cars]

Could it go to the temperature sensors located on the back of the thermostat manifold? If its from one of those it wont make any difference. Only thing i can think of that could possibly plug into the gearbox at the rear is the speed sensor plug, that would be right above the offside driveshaft where it enters the speedo drive housing. This could be the one though seeing as you have abs fitted? Also wont matter which way round.

[Luke 7 1 Cars]

As long as it doesn't matter which way round it goes that's fine by me!

 

Ta