Reg plate lights work occasionally

[2011dandd]

Hi guys as the title suggest I am having problems with the registration lamps. R/h one doesn’t come on, left hand comes on and off at will. I need to investigate to see what’s going on, but wanted to ask here first incase there is a common fault here. Also the rear window wiper can play up and does not always come on when I want to to

[Clifford Pope]

What are registration lights?

[loki_the_glt]

Take the assemblies out and bend the bulb-holder clips GENTLY towards each other, cleaning them if they show signs of pitting. Over time the spring steel loses its springiness. While you're at it, clean up the terminals and the caps on the end of the (festoon?) bulbs.

[2011dandd]

Originally Posted by loki_the_glt

Take the assemblies out and bend the bulb-holder clips GENTLY towards each other, cleaning them if they show signs of pitting. Over time the spring steel loses its springiness. While you're at it, clean up the terminals and the caps on the end of the (festoon?) bulbs.

Thanks for the advice. I have already done all this but it’s made no difference, I will have to have a look for a bad earth or a wire that’s compromised

[Laird Scooby]

Originally Posted by 2011dandd

Hi guys as the title suggest I am having problems with the registration lamps. R/h one doesn’t come on, left hand comes on and off at will. I need to investigate to see what’s going on, but wanted to ask here first incase there is a common fault here. Also the rear window wiper can play up and does not always come on when I want to to

Big clue in red there ^^^^^ Sounds like one of two probable causes, the wiring loom where it passes from body to tailgate has probably developed some broken wires and secondly, the earth to the tailgate and/or wiper motor/number plate light bulbs could be bad. Factor in a loose connector or two on the number plate lights and you've got a recipe for your exact symptoms.

Open the tailgate with the sidelights on and wiggle the loom between body and tailgate, see if the lights start behaving - ditto with the rear wiper on.

[2011dandd]

Cheers Dave

I think you are right, I reckon it’s at the body to tailgate big of the loom. The peculiar thing is, when I press the button to open the tailgate it acts like a switch, also pressing on the tailgate when closed acts like a switch

[Laird Scooby]

Originally Posted by 2011dandd

Cheers Dave

I think you are right, I reckon it’s at the body to tailgate big of the loom. The peculiar thing is, when I press the button to open the tailgate it acts like a switch, also pressing on the tailgate when closed acts like a switch

Worth investigating the are round the latch and the remote button then too, could be something as simple as a broken earth connector or wire.

[Stephen Edwin]

Originally Posted by 2011dandd

Hi guys as the title suggest I am having problems with the registration lamps. R/h one doesn’t come on, left hand comes on and off at will. I need to investigate to see what’s going on, but wanted to ask here first incase there is a common fault here. Also the rear window wiper can play up and does not always come on when I want to to

Hello and this sounds like an estate.

Physical inspection and a test lamp &c. will determine whether the two lamps have [entirely] separate electrical supplies or not.

As one lamp does not come on and the other is intermittent, I suspect that the lamps are both past their best before date. You have tried refurbishing them. I suggest that you give them both a well deserved retirement. Even if you need to do further work re the wiring, those lamps are probably, knackered, by now.

On my estate, replacing both number plate lamps with (genuine Volvo) brand new lamps entirely solved a similar problem.

Those lamps are a simple design. The springy metal holds the lamp in place, holds the bulb and makes electrical contact withe the bulb ends and contact with the tailgate as earth. That is either brilliant design or too clever by half.

Good luck.


.

[2011dandd]

Cheers guys

The replacement lamps, have only seen these available at a hefty price

[Othen]

Originally Posted by 2011dandd

Cheers guys

The replacement lamps, have only seen these available at a hefty price

... I've just scanned through this: replacing the whole luminaire assemblies would be an absurd (and very expensive) solution. If the lights work sometimes the problem must be just an intermittent electrical connection. Clean up all the contacts and then look for a break or bad earth with a multi-meter, probably at an articulated joint (so between the body and the door.

The cable Volvo used (and particularly its insulation) back in the day was pretty poor quality (I had to make a complete new loom for the engine compartment on my 244 to fix it), so I'm pretty sure that will be the problem.

Good fortune.