alan.barker wrote:+1
Imho the ACR17 is rated correct and that's why Lotus fitted it to later +2 Elans.
Alan
Alan,
I don't want to seem to be picking up on your points, but I am not sure this is correct. The original C40L Lucas dynamo was rated with a maximum output of 25 amps. The 17ACR is rated at 36 amps.
The only time the 17ACR would be producing 36 amps on the Elan would be at high revs into a flat battery with all the electrics on, but in principle, it could happen. The original wiring from the dynamo to control box, and then on to the battery on earlier cars went via a dash mounted ammeter, and was (IMHO) marginal at best. Fitting a 17ACR to this setup is asking for trouble. I believe the later cars had a battery voltage meter dispensing with the extra loop of cable.
Were it me fitting any alternator to an Elan, I would dispense with the original connections to the dynamo and control box and run a new, suitably sized cable direct from the alternator to the battery side connection on the starter relay. If I really wanted to keep the ammeter, then replacing the ammeter loop with a thicker cable is probably a good idea.
This doesn't detract from your point that you can't just put any old alternator on an Elan and not consider that wiring implications - which I agree with, but even a humble 17ACR needs some thought before fitting.