Page 1 of 1

Number Plate Lights

Posted: Sat Jul 25, 2020 9:03 am
by D366Y
Morning all,

I think I know the answer but just wanted to double check - the rear number plate lights are earthed via the holder and screws that hold them in place correct? One had stopped working so took it off the other day, the bulb was fine, put it back on after I'd cleaned it up a little and the other one stopped working, but it did make the rear brake light work by both of the number plate lights not working :lol:

Capri wiring really is a dark art at times

I also think that the housing for one of the bulbs is cracked so will that affect the earthing? Also the screws are an absolute state and aren't too dissimilar to how I'd imagine the Titanic currently looks - are replacements available as I have no idea of the sizes?

Cheers
Danny

Re: Number Plate Lights

Posted: Sat Jul 25, 2020 9:11 am
by Andrew 2.8i
D366Y wrote: Sat Jul 25, 2020 9:03 am I think I know the answer but just wanted to double check - the rear number plate lights are earthed via the holder and screws that hold them in place correct?
Yes, you are correct.
The thread size is a standard M6 thread, but why bother replacing them? They should clean up easily enough with a wire brush.

Andrew.

Re: Number Plate Lights

Posted: Sat Jul 25, 2020 12:53 pm
by D366Y
Andrew 2.8i wrote: Sat Jul 25, 2020 9:11 am
D366Y wrote: Sat Jul 25, 2020 9:03 am I think I know the answer but just wanted to double check - the rear number plate lights are earthed via the holder and screws that hold them in place correct?
Yes, you are correct.
The thread size is a standard M6 thread, but why bother replacing them? They should clean up easily enough with a wire brush.

Andrew.
Thanks Andrew, the problem is that one of the heads has completely gone and looks like a giant square rather than something I can a screwdriver in so thanks to whoever owned the car before me! :wave:

Will likely have to drill that one out but will try cleaning up the others and see what happens. If the cover is cracked will that affect the lights? I know the rear light clusters have a habit of not working when they crack so didn't know if this was the same?

Thanks
Danny

Re: Number Plate Lights

Posted: Sat Jul 25, 2020 1:37 pm
by Andrew 2.8i
D366Y wrote: Sat Jul 25, 2020 12:53 pm If the cover is cracked will that affect the lights? I know the rear light clusters have a habit of not working when they crack so didn't know if this was the same?
I don't think so, I think the earth connection is made through the backing plate. From what I remember, the cover is completely made from plastic.

I didn't realise your existing screws were that badly damaged, you might as well buy replacements after all. 16mm should be around the right size.
https://www.ebay.co.uk/itm/POZI-PAN-MAC ... SwKA5b2bHl

Andrew.

Re: Number Plate Lights

Posted: Sun Jul 26, 2020 9:23 pm
by STEVEW
D366Y wrote,
the rear number plate lights are earthed via the holder and screws that hold them in place correct?
I believe the earth works via a fine cylindrical metal sleeve in the plastic body. When the retaining bolt is inserted and tightened the head of the bolt contacts the end of the ring and makes the earth.
After time the bolts and or the metal sleeve erode which creates an "air gap" between bolt and sleeve so there's no earth. I suspect people then give the bolt an extra turn which could temporarily solve the problem but it can also crack the housing.

I solved this problem by doing the following:

Parts
- Half-round headed screw which takes a 4mm allen key (18x6mm) (x4)
- Serrated lock washer 6mm (x4)
- Plain washer 6x14mm (x4)
- Insert washer 6x10mm (This should fit into the bolt hole to act as a bridge between the larger plain washer/bolt head and the sleeve.)
! The insert washer should sit flush with the lamp cover and the bolts should be gently tightened.

Since doing our number plates like this we have had no problem.

I've tried to upload a picture but unfortunately it hasn't worked.
I have however, written a couple of articles (Why a Capri) about some of the problems and how we solved them, in preparing our Capri for the road. The number plate problem appeared in the January 2019 edition of the CCI club magazine and there is a photo included.
These articles were written to help people solve some problems they may encounter.
All the best.
Steve

PS. If you have any other questions about this, please ask.

Re: Number Plate Lights

Posted: Mon Jul 27, 2020 7:39 am
by STEVEW
Correction

The article appeared in the January 2018 edition of the CCI magazine.

Re: Number Plate Lights

Posted: Mon Jul 27, 2020 9:22 am
by Mc Tool
There is no real reason you cant run a separate earth wire from the light fitting to the chasis. I have had to fix both tail and headlight wiring ,not just an age thing either ( I mean the car ....not me ) the headlights got redesigned ......before I found out about the bmw angel eyes :roll:

Re: Number Plate Lights

Posted: Mon Jul 27, 2020 10:11 am
by Bug
I took the old screws out, cleaned up the metal insert, then replaced the screws with 10mm hex bolts which came from somewhere else on the car, can't remember where after all these years.Might have been mounting bolts from under the dash somewhere?
A word of caution though. I once thought I'd be clever and use stainless steel bolts. Took a while to cotton on and realise I needed to use a metal that was actually conductive! :doh:

Re: Number Plate Lights

Posted: Mon Jul 27, 2020 11:29 am
by D366Y
Mc Tool wrote: Mon Jul 27, 2020 9:22 am There is no real reason you cant run a separate earth wire from the light fitting to the chasis. I have had to fix both tail and headlight wiring ,not just an age thing either ( I mean the car ....not me ) the headlights got redesigned ......before I found out about the bmw angel eyes :roll:
I did think about this option as well as it would be a lot easier to have a proper earth - I'll have to take them out and have a look when I get some time over the next couple of days

Thanks for the replies as ever, will let you know when it all goes wrong :lol:

Re: Number Plate Lights

Posted: Wed Nov 04, 2020 8:36 am
by D366Y
Andrew 2.8i wrote: Sat Jul 25, 2020 1:37 pm I don't think so, I think the earth connection is made through the backing plate. From what I remember, the cover is completely made from plastic.

I didn't realise your existing screws were that badly damaged, you might as well buy replacements after all. 16mm should be around the right size.
https://www.ebay.co.uk/itm/POZI-PAN-MAC ... SwKA5b2bHl

Andrew.
It only took me four months to order and fit these screws.... :lol:
It did solve the problem though so thank you Andrew for the link and suggestion!

Re: Number Plate Lights

Posted: Thu Nov 05, 2020 7:26 pm
by Mc Tool
Bug wrote: Mon Jul 27, 2020 10:11 am I took the old screws out, cleaned up the metal insert, then replaced the screws with 10mm hex bolts which came from somewhere else on the car, can't remember where after all these years.Might have been mounting bolts from under the dash somewhere?
A word of caution though. I once thought I'd be clever and use stainless steel bolts. Took a while to cotton on and realise I needed to use a metal that was actually conductive! :doh:
Im pretty sure stainless steel conducts elictrickery......how else would you tig weld it ? :)

Re: Number Plate Lights

Posted: Thu Nov 05, 2020 7:55 pm
by STEVEW
D336Y,
Maybe this photo could help you.

The additional washers look rough but that's because of the magnification. They form a "bridge" between the original (corroded?) conductive insert and the bolt head. The bolt itself forming the earth circuit to the captive nut.
Overtightening in an attempt to close the "erosion gap" cracks the housing.

Regards,
Steve

Re: Number Plate Lights

Posted: Fri Nov 06, 2020 9:20 am
by D366Y
STEVEW wrote: Thu Nov 05, 2020 7:55 pm D336Y,
Maybe this photo could help you.

The additional washers look rough but that's because of the magnification. They form a "bridge" between the original (corroded?) conductive insert and the bolt head. The bolt itself forming the earth circuit to the captive nut.
Overtightening in an attempt to close the "erosion gap" cracks the housing.

Regards,
Steve
Cheers Steve,

My old washers were rusty as anything so maybe that was why they weren't working.... didn't use washers this time but will get some and whack them on.

Cheers
Danny

Re: Number Plate Lights

Posted: Fri Nov 06, 2020 9:35 am
by Bug
Mc Tool wrote: Thu Nov 05, 2020 7:26 pm
Bug wrote: Mon Jul 27, 2020 10:11 am I took the old screws out, cleaned up the metal insert, then replaced the screws with 10mm hex bolts which came from somewhere else on the car, can't remember where after all these years.Might have been mounting bolts from under the dash somewhere?
A word of caution though. I once thought I'd be clever and use stainless steel bolts. Took a while to cotton on and realise I needed to use a metal that was actually conductive! :doh:
Im pretty sure stainless steel conducts elictrickery......how else would you tig weld it ? :)
Well these buggers wouldn't!
I'm no elektrishun though, but I assumed that was the case. Stuck normal metal in and it worked fine.
The bigger point of my post really was that I used bolts as they are much less likely to round off the next time you want them out.

Re: Number Plate Lights

Posted: Fri Nov 06, 2020 5:01 pm
by Andrew 2.8i
D366Y wrote: Wed Nov 04, 2020 8:36 am It did solve the problem though so thank you Andrew for the link and suggestion!
Hi Danny, glad you got it sorted. After only four months too ! :D

Andrew.

Re: Number Plate Lights

Posted: Fri Nov 06, 2020 5:10 pm
by D366Y
Andrew 2.8i wrote: Fri Nov 06, 2020 5:01 pm
D366Y wrote: Wed Nov 04, 2020 8:36 am It did solve the problem though so thank you Andrew for the link and suggestion!
Hi Danny, glad you got it sorted. After only four months too ! :D

Andrew.
New personal best for me! I ordered the screws last week and only took me a week to fit them... in my defence I have been busy .... :whistle: .... avoiding this for a while :lol:

For a five minute fix I wish I'd just done it at the time haha

Re: Number Plate Lights

Posted: Fri Nov 06, 2020 7:23 pm
by Mc Tool
I can beat that . I fix ( used to ) appliances ....inc ovens....Di waited patiently ( not quietly ) for 12 years for me to fit a new thermostat to her oven .....then we moved to Nelson where we got a new wiermarana black lab X pup .......dog died of old age before I built the promised kennel .....more a penthouse suite which might have been the problem