Alternator failure

[tahiti450]

Hi folks,
Posting this mainly for info and possibly some advice. 1999 chim 450. Alternator (magnetti Marelli A127 - 100A LR part no AMR 4247) packed up at the w/e, not charging and charging light on at idle. Tried the usual rescuscitation this afternoon by fitting a new regulator (£30 form local auto electrical supplier)incidentally this assembly includes the brush box and brushes.
sadly no joy , so probably the rectifier (doides) that have failed, unless someone has a different suggestion... anyone?
Apparently the rectifier is not practical to service as it is spot welded onto the stator / field winding assembly (although I haven't investigated this and I have previously repaired an earlier A127 by changing the rectifier).
I am now browsing for prices on a replcement alternator. Am getting prices of around £150 outright for what I am assured is a new OEM branded item from various landrover parts suppliers, with next day delivery ( I note that some of the main agents are talking over £300 and my local auto electrical supplier recons around £220). Anyone got any observations, suggestions as regards fixing the original or on the prices quoted?

>> Edited by tahiti450 on Tuesday 28th June 22:02

[chim500tom]

I assume that you've checked the 100amp fuse first off? It was the fuse that was the problem when I had a similar issue, not the alternator.

[tahiti450]

chim500tom said:

I assume that you've checked the 100amp fuse first off? It was the fuse that was the problem when I had a similar issue, not the alternator.

Ah yes, of course - that is in series with the main alternator cable (presumably to protect the alternator from short circuits etc). In short - it hadn't occurred to me... no I haven't, but I shall!!! Fingers crossed. Thanks very much.

[parrot of doom]

If you have to replace it, get an exchange unit - will save you a fair bit of cash.

[tahiti450]

chim500tom said:

I assume that you've checked the 100amp fuse first off? It was the fuse that was the problem when I had a similar issue, not the alternator.

Spot on my friend!
Quick check of the voltage at the alternator main terminal showed 0 volts so clearly fuse gone. Fuse not only blown but the holder had melted so that the fuse to battery cable was hanging loose, with a lump of melted plastic on the end! Now just need to source a new fuse.
Many thanks Tom.

>> Edited by tahiti450 on Tuesday 28th June 19:02

[tahiti450]

I've just seen the link to the 100A fuse thread on Tom's profile so now I know exactly what to do, i'll be needing a new holder as well. brilliant.

I note David Beer's comment that bypassing the fuse isn't really a problem, which is in fact what I have done pending the new fuse. The TVR is the only car I've come across that has a fuse in this circuit. I can see that without a fuse (to stop xs current) in a major accident the alternator could get shorted to earth, cause the cable to fry and present a fire risk. Is it because of the non-fire-tolerant GRP body that this is fuse felt to be needed?