My "NextGen" generator stopped working when we were on our way to Ireland. Nothing unusual about this - happens all the time! I've gotten quite familiar with my beloved generator!

Unfortunately, this time I couldn't fix it... I looked at wiring, capacitor, sensors... nothing! I determined that there must be something wrong with the alternator itself - windings? This was going to take a while - so we'd wait until we were in one place for a decent period.

When we arrived in our winter berth in the UK, I lifted the generator, separated the alternator and took it to a Park Gate in Carlisle to get the windings done - whatever that means... They took it apart and checked it over and decided the windings were fine!

Perhaps it's the diodes? Unfortunately, the place I took it to were uncomfortable going further - they prefer working on bigger stuff. I think I got lucky - even though they spent time looking into the project, becasue they couldn't fix it, they didn't charge me...

I managed to find someone who used to work on this brand of alternator - a Markon BL105 - and he agreed the Diodes were a possibility and guess what - he can supply them - I just need to ID which ones mine has... So I send a photo and he's not seen anything like it! The theory we have is that probably my unit was built in Mexico - after the Markon factory closed in the UK, they moved it to Mexico - it's since closed altogether. While in Mexico, we think they may have done a fairly typical 'cost out' program on the Alternator and come up with cheaper diodes...

My next problem is that my soldering skills are non existent - and since Park Gate felt uncomfortable about it... Fortunately, I have found someone (Chris Dobson) right here in Whitehaven that's willing to 'give it a go' - what do I have to lose?

So now the burning question is will a standard UK diode arrangement fit in my unit and will it work? Will Chris be able to come up with the soldering capability...

Stay tuned for the next installment!



Anybody else had problems with diodes in large alternators??

Bill Balme

Hi Bill,
More time now.
I would stop thinking yourself about what it could be; we are not the experts. And start hammering those who should know: Next Gen, alternator company etc. With Next Gen, I would make clear that you will be writing about this and that you want to portray them in the best light: so please help. If necessary, offer to pay for the consult (they should not accept, but it lets them know how serious this is to you). Push hard to talk to the president or very senior people.
I would also consider finding an expert to look over your shoulder (verbally) at what has been done, the results, the history etc. You will likely have to pay him, but that is OK: that’s his/her job. I have done this a few times with someone I have an ongoing relationship with with good success.
I would consider doing this with Rod at https://marinehowto.com/contact-2/. I think he is superb in all he does, but I am not sure his expertise is in this area. If not, I would ask him to suggest someone.
Good luck, Dick