Thanks guy's.
Our story of woe is;
Previous owner (
[email protected]) had the original alt. modded for higher output but the result was it wouldn't charge at idle. Always given me the irrits!
Matt recently replaced the battery. The new battery was larger(physically) then the previous one and now fills the original battery box.
[email protected] had also fitted one of those massive bronze/brass multi-point clamp's on the pos. side.
Unbeknown to us, the new battery length had moved this monster clamp forward in the engine bay. This meant that when the bonnet was closed, the clamp was hard-up against the bonnet 'rails' on the underside. Because the sound/heat proofing bonnet lining was squished between clamp and bonnet, there was no shorting.
This changed the other night when, it would appear, the lining finally wore through and KABOOM! Loss of all power, backfire, no charge. The monster terminal looks like someone was trying to start an arc with a stick welder!
I suspect the diode pack has blown but am open to ideas.
Bottom line is, the alternator is not charging at all.
Someone else on the forum suggested rebuilding the old one by filling it with high output Bosch stuff rather than replacing it.
Might go that route I think.
Thanks again.