Reverse lights not working ! Help!!

[herman_t25]

Hi all,

Doing my final checks before the MOT tomorrow and the reverse lights aren’t working.

I’ve scoured the forum and checked so far

Bulbs. Fitted led ones recently but swapped those and the old ones. Only lamps I didn’t check when I fitted the led kit as I was alone

Reverse switch, when I checked it one of the spades was unplugged. Wasn’t that. Removed and cleaned. Fitted with and without washer. Tried tightening while running to see if the lamps come on. Don’t appear to be getting voltage at the spade connectors.

Checked the fuse, fitted a new one. Horn works too. Voltage at the fuse box for it.

Any other things I can check?

[Swissy0]

I think it might be negative switching can't remember but mine was the same just cleaned up the terminals and put on fresh crimps ,get someone in the van to operate reverse gear use a multil meter on ohms or the buzzer is easier make sure the switch is operational just test one probe on each terminal

[herman_t25]

Thanks Swissy I tested in ohms, while running. Reading was continuously changing but not reading zero?

I may try re crimping the cables now failing that guess I order a new switch to eliminate that.

[Robsey]

The reverse light is fed from the fusebox as follows:-

Fuse to engine-bay junction box (black / blue).

Two (black / blue) wires go to the gearbox switch.
One to feed switch, and one back again to junction box.
From the junction box to the right rear light cluster.

There is a brown earth wire to the cluster, which is attached to the left engine-bay wall.

-----------------------

To answer your description...
The lights are switched live, not switched ground.

----------------------

Have you tested the switch itself.?

Unplug both lucar (female spade) connectors from the switch and short together.
The lights should come on with the ignition on.

If the light does not come on, then it is either a feed or ground issue.

If the light comes on, then it is a switch or detent plunger issue.
The operating plunger should push the switch contact.
The plunger can become worn and no longer depresses the switch detent enough.
Also to confirm that the washer should be in place under the switch.

---------------------------

[muttleypup]

Try bridging both spades together with a short wire, if lights are on it's the switch.  If so, try spraying WD40 or similar into the plunger hole and work it in and out with finger several times.  Might be gummed up inside, worked for me.

[herman_t25]

Thanks both, bridged the spade connectors and still no lights? Where is best to check first?

[Robsey]

Using a test meter - you need to follow the wiring from the fusebox, all the way to the tail light.
Checking for 12 volts at each junction.

2nd thought,
have you tried running a temporary wire from the fusebox to the switch.?

This will get 12 volts to the switch.
After that, if the lights still do not come on, then it has to be a bulb, cluster or earthing issue.

Obvious question...
LED bulbs - did you fit them the right way round?
Are the old bulbs LEDs or standard filament bulbs?
Obviously only the LED bulbs require the correct polarity / orientation.

[Oldiebut goodie]

Reverse lights are not part of the MoT as far as I am aware ( unless it has changed without me knowing ).

[slowcoach]

There's a coupling for the reverse lights in the black box in the engine bay, it has square yellow connectors. worth checking those too.

Sent from my Pixel 4 using Tapatalk

[tobydog]

https://www.gov.uk/government/news/mot- ... 0-may-2018


Some new items are tested during the MOT.

They include checking:
    reversing lights on vehicles first used from 1 September 2009

[herman_t25]

Reverse lights are not part of the MoT as far as I am aware ( unless it has changed without me knowing ).

My thoughts too but the gov website says it is! We shall see how strict it is

[herman_t25]

There's a coupling for the reverse lights in the black box in the engine bay, it has square yellow connectors. worth checking those too.

Sent from my Pixel 4 using Tapatalk

Cheers I’ve checked, found some other quite scaring looking wiring though

[herman_t25]

Using a test meter - you need to follow the wiring from the fusebox, all the way to the tail light.
Checking for 12 volts at each junction.

2nd thought,
have you tried running a temporary wire from the fusebox to the switch.?

This will get 12 volts to the switch.
After that, if the lights still do not come on, then it has to be a bulb, cluster or earthing issue.

Obvious question...
LED bulbs - did you fit them the right way round?
Are the old bulbs LEDs or standard filament bulbs?
Obviously only the LED bulbs require the correct polarity / orientation.

Thanks Robsey, I’ll try running a direct wire tomorrow. The old lamps were filament. I kept them and tried them again. No luck

[Oldiebut goodie]

Reverse lights are not part of the MoT as far as I am aware ( unless it has changed without me knowing ).

My thoughts too but the gov website says it is! We shall see how strict it is

Surely your vehicle was first used before 2009?

[herman_t25]

Reverse lights are not part of the MoT as far as I am aware ( unless it has changed without me knowing ).

My thoughts too but the gov website says it is! We shall see how strict it is

Surely your vehicle was first used before 2009?

Ah I read that wrong! It’s definitely older than 2009