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Bulb holders; intermittency.
http://forum.triumphdolomite.co.uk/viewtopic.php?f=6&t=33895
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Author:  MIG Wielder [ Fri Apr 27, 2018 1:05 pm ]
Post subject:  Bulb holders; intermittency.

I reckon the worst thing to fail an MOT test on is an intermittent bulb-holder. Particularly at the back.
This seems to be a particular problem on cars that are not used very much; simply because the heat from the bulb in use tends to drive out moisture.
Replacement is one solution, and these bulb holders are the same as those fitted to the Spitfire, the Stag and also some Lotus models from the '70s. The Stag Owners Club always have lots of them on their stands at the Shows at a good price but I recently helped to work on a Sprint on which there was nothing lighting up at the back. In this case each bulb-holder's terminals, the connectors, the internal spring connectors all needed cleaning out before it worked.
There was one reversing light which proved to be much more of a problem than the others. The bulb by itself was O.K., the bulb connected across the wiring was O.K.; the contact springs were clean but it still refused to work.
The problem is in the design; the side copper contact that touches the bulb runs up the side of the holder and ends up under the plated mild steel of the surround. If moisture gets in here it corrodes and isolates this ground contact.
Solution: scrape the copper and mild steel clean and run a film of solder between the two. Surprisingly the mild steel solders quite well.
Sorted!

Attachments:
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Author:  Mad Mart [ Fri Apr 27, 2018 2:27 pm ]
Post subject:  Re: Bulb holders; intermittency.

:thumbsup: Exactly what I do Tony. I got fed up with trying to get a good connection.

Author:  Richard the old one [ Fri Apr 27, 2018 7:56 pm ]
Post subject:  Re: Bulb holders; intermittency.

Hi Tony.

I have started to draft what Steve is going to call Richard Old's A to Z on dolomites for inclusion in Dolly mixture in which I will attempt to give tips etc that I have picked up over the years. Will it is o.k for me to include this advice which is something new as far as I am concerned.

Richard

Author:  new to this [ Fri Apr 27, 2018 9:12 pm ]
Post subject:  Re: Bulb holders; intermittency.

Thats a good idea

Author:  MIG Wielder [ Sat Apr 28, 2018 11:30 am ]
Post subject:  Re: Bulb holders; intermittency.

Quote:
Hi Tony.

Will it is o.k for me to include this advice which is something new as far as I am concerned.

Richard
Hi Richard, Yes, no problem please do use this if it helps.
Cheers for now,
Tony.

Author:  tony g [ Mon Apr 30, 2018 2:22 pm ]
Post subject:  Re: Bulb holders; intermittency.

Great tip Tony, will a decent soldering iron be good enough to solder to the steel ring?

Cheers

Tony

Author:  MIG Wielder [ Tue May 01, 2018 3:38 pm ]
Post subject:  Re: Bulb holders; intermittency.

Hi Tony, I have a 25W Weller TCP1 with a selection of bits. That manages just fine. I tin the mild steel bit first with cored solder and scraping the steel with the point of the iron under a pool of flux and solder, and then when its tinned nicely I run a small fillet of solder down onto the top of the copper contact.
Tony.

Author:  tony g [ Thu May 10, 2018 12:12 pm ]
Post subject:  Re: Bulb holders; intermittency.

Thanks Tony,I'll try on a couple of spares I have :thumbsup:

Tony

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