Morris Minor Owners Club

Hi, can anybody advise:-
convertible needed new sealed beam for its mot. Sent for one off eBay and connected it up. Illuminated on main beam for maybe 2-3 seconds then extinguished. Tried it on dipped and same occurrence. Do I conclude that I've 'blown' the unit? If so why/ how? Can't see anything obviously wrong with wiring, any ideas?

It likely has a leak somewhere, allowing the inert gas out and air in. Air plus white hot filament is not a good combination - and they did! May not have been degassed properly at manufacture. Nothing to do with your car being a convertible!

Could also be a 6 volt unit on 12 volts? Never seen a 6 volt sealed beam unit, mind.

Thanks for this, definitely not a 6v. Thanks for eliminating convertible issue! No sign of seal failure, I'd no obvious cracks etc!

Secondhand sealed beam units, unused for a long time, often seem to have very short lives. They are usually very reliable but last time I had to replace one, I found 2 or 3 working spares in my garage. Once fitted though none of them lasted long
They don't seem to like sitting on a shelf for years on end.......

For the work and effort involved do the halogen conversion, they work just fine and all you have to do is change an H4 bulb then.

I don't drive her at night much but on the occasions I have the lights are pretty good, and more than enough for what the car is.

Old sealed beams often blow - the air leaks in over time, especially when not 'used' when tiny amounts of air would be burned up by the filament as it goes along. Generally a waste of money buying old sealed beams - I dumped at least 6 old ones without even bothering to test them, which I had 'saved over the years ' a couple of weeks ago.

Thanks all! Quite a consensus regarding the sense in fitting second hand sealed beams! Halogen replacements now on order!
Thanks again for your collective expertise!