Rover 100 Electrics

Did you charge the battery to at least 70% and check for a dead cell BEFORE trying to test the alternator ? It suspect either the battery could have a dead cell charge it fully and do a cranking voltage test or it could be a deffective diode pack in the alternator, very common on Lucas-Magneti Marelli alternators, the way to check for this is to check for reverse current back through the alternator main terminnals.

Also check all the electrical system earth conections and check the spades on the 3 blade connector plug isn't erroded away by arcing.

"John" mumbled:

I think you'll find that there's a "fusible wire" segment...part of the wiring harness is used as a fuse! Gruesome, innit?

I finally found the problem. Just as you say there is a fusible segment which is about 100mm length of thinner wire. the Alternator output sets off from the Alternator in brown about 10mm^2 and goes round the back of the engine then comes back to the front at the starter motor end. It changes down to about 6mm^2 for the final 100mm inside a plastic sleeve then attaches to the starter/battery main power lead via a crimped eyelet. This eyelet had corroded away and vanished. I think the old alternator had been damaged by the lead end shorting to frame when it flapped about. I made up a new connection. All now would appear to be in order and the battery is charging when the engine is running.

I'm not impressed with the overall design of the model from having to remove the whole oil filter assembly from the block simply to remove the alternator to the wasted time spent looking for a connection which I expected to reappear in the same size conductor at each end of its run IMHO its a pigs breakfast. Thanks for the pointer though.

-- Please note antispam measures - do not hit reply Horse sense is what horses have that makes them not bet on people - W.C. Fields

Regards, John