BBB charger unit packed in

[syncro4us]

Just ben sorting  the VW Syncro BBB Charger unit as it had packed in.
Its been in since 1986 when Westfalia  made the conversion.
1-First thing I did was to check the breaker so hooked up to Mains
2- trip worked pushing the button it threw out and locked back in to provide mains to van
3- tested mains feed to BBB charger and it was 240 volts so ok
4- took top off BBB to check internal fuse that proved ok
5- checked the primary and secondary windings for break and -both ok
5- tested to see how far the 240 volts went past fuse holder but not past the thermal fuse
which was OS
6- temporarily bridged the thermal switch terminals with piece of wire and the charger worked fine with trickle charge of 13.2 odd volts to the leisure battery and 14.3 volts to the crank battery so split charge seems ok.With the electronics control board I suspect it gives priority and higher charge to the crank battery tha draws far more current and just a top up charge for the leisure battery so will look for output specs if there are any official ones
6- have ordered new thermal switches  (pack of 5 X 240 volt 3amp 130 Celcius blow £5 or so £6 postage outrageous!) and will solder one  into circuit later on to get the VW back up and running
7- blew away all the crud and bits from the BBB after 39 years use and cleaned the transformer and heat sink etc with isoproprinol on cotton bud to allow for the best heat transfer to atmos as  low batteries put quite a power demand on the unit which is flogging its heart out at the best of times. This cleaning reduced the buzzing from the power unit a lot so suspect the crud was causing the 240volt 50 Hz step down transformer to magnify any resonance but now quiet as a lamb.

[pirate-pete]

Sounds like the same as my last van.  Didn't work when I bought it over 15 years ago.  Sorted the thermal fuse and it gave me no problems until the end of my ownership over 10 years later.   Just got another Westy now which still has the BBB.  Not yet got round to testing it as first thing I did was to go for a long trip and I have not been anywhere yet with a hookup cable.  I know the fridge won't work as I was told that before purchase and have already tested and removed the element.  So not really worth paying for hookup if the fridge does not need it and the gas is now working.  Well done for getting it going again.  A lot of people here dont trust the BBB, but I liked the way my old one worked with keeping the two batteries charged so never saw a reason to change.  With the new one I might change some capacitors just to make sure they are running to spec - most other components other than the thermal switch will probably be fine.