Vehicle electrics advice

[eggsarascal]

MOT first thing in the morning, leave my mates place earlier, he says, ya know the reverse lights aren't working.

 

Changed fuse, new bulbs, shorted out switch, still no reverse lights. I'll clean the earth's up after ive fed. Failing that it's a break in the loom?

 

 

[Squaredy]

42 minutes ago, eggsarascal said:

MOT first thing in the morning, leave my mates place earlier, he says, ya know the reverse lights aren't working.

 

Changed fuse, new bulbs, shorted out switch, still no reverse lights. I'll clean the earth's up after ive fed. Failing that it's a break in the loom?

 

 

It looks to me as if reversing lights not working is NOT an MOT failure.  I suggest you check, but that is what a quick Google search suggests.

[eggsarascal]

37 minutes ago, Squaredy said:

It looks to me as if reversing lights not working is NOT an MOT failure.  I suggest you check, but that is what a quick Google search suggests.

Yep, read that earlier. Looks like that's what I'll be going with if they try to fail it on the lights, cus I can't get them to work.

[Oldfeller]

what vehicle is it, are the reverse lights triggered by a hyd switch in the braking system, or an electrical switch, often located and operated by the brake pedal, either way find it and join the two wires momentarily together, if the lights come on its a faulty switch, if they  don't or it blows a fuse, it's likely a wiring fault.

post 2009 vehicles must have one working reversing lamp, you can wire directly to a switch and bypass the fault but you must have a visible warning light clearly seen from the driver seat.

[not necessary if operated by engaging reverse]

Edited Sunday at 22:07 by Oldfeller

[eggsarascal]

30 minutes ago, Oldfeller said:

what vehicle is it, are the reverse lights triggered by a hyd switch in the braking system, or an electrical switch, often located and operated by the brake pedal, either way find it and join the two wires momentarily together, if the lights come on its a faulty switch, if they  don't or it blows a fuse, it's likely a wiring fault.

post 2009 vehicles must have one working reversing lamp, you can wire directly to a switch and bypass the fault but you must have a visible warning light clearly seen from the driver seat.

[not necessary if operated by engaging reverse]

I don't mean to be rude Oldfeller, but did you not read the bit where I said I'd shorted the switch? No dash lights. Citroen Relay 57 plate.

[Oldfeller]

22 minutes ago, eggsarascal said:

I don't mean to be rude Oldfeller, but did you not read the bit where I said I'd shorted the switch? No dash lights. Citroen Relay 57 plate.

sorry I missed that bit, looks like you been through it pretty thoroughly, can you jury rig a reverse lamp using the lights[or one of them] and a bit of temporary wiring, get the ticket and investigate after, vehicle construction and use regs state if a light is fitted on a vehicle it must work, and post '09 reversing lights are mandatory. 

[eggsarascal]

56 minutes ago, Oldfeller said:

sorry I missed that bit, looks like you been through it pretty thoroughly, can you jury rig a reverse lamp using the lights[or one of them] and a bit of temporary wiring, get the ticket and investigate after, vehicle construction and use regs state if a light is fitted on a vehicle it must work, and post '09 reversing lights are mandatory. 

If I'm reading it correctly it's not an MOT fail, but it's a legal requirement if reversing lights are fitted?

[Oldfeller]

7 minutes ago, eggsarascal said:

If I'm reading it correctly it's not an MOT fail, but it's a legal requirement if reversing lights are fitted?

MOT inspection manual: cars and passenger vehicles - 4. Lamps, reflectors and electrical equipment - Guidance - GOV.UK

WWW.GOV.UK

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Headlamp, position lamps, daytime running lamps, stop lamps, indicators, hazard...

 

[eggsarascal]

7 minutes ago, Oldfeller said:

MOT inspection manual: cars and passenger vehicles - 4. Lamps, reflectors and electrical equipment - Guidance - GOV.UK

WWW.GOV.UK

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Headlamp, position lamps, daytime running lamps, stop lamps, indicators, hazard...

 

OK, you've read what I've read, catch ya tomorrow, MOT'd or not!

[Muddy42]

Sorry if you have done this, but Id suggest lots of testing with a multimeter first to isolate the issue and map out how the electrics work.  Not sure what car it is, but I check with the engine running rather than just with the ignition on.

 

I use a crocodile clip to extend the multimeter to battery negative or known earth.  Check for voltage with each part of the wiring - battery to fuse, check fuse, to switch, to light.  Then check continuity to light's earth. 

 

As above, once you have found the part of the system that's not working, crawl around and look for obvious issues or just bypass the standard wiring.