New Alternator
Right, a quick re-cap. HTU now starts, moves about & stops under her own steam. This must be progress.
But wait.... why is that red light staying on ?
Yep, a glance at the ammeter confirms it, the alternator has gone on strike. Ten minutes with a meter and fault finding chart and I’m no wiser other than it’s SNAFU. (If you don’t recognise that acronym, this is a family site so look it up on google)
The alternator was the original unit which I don't recognise and no doubt has long since ceased production. But the Elan has a Lucas 16ACR unit and as similar 17ACR units are available for around £50 brand new, this is beginning to look like a no-brainer.
Lucas 17ACR Alternator
The OEM wiring needs modification as the loom has 4 connections, one each for the charge warning light, +12v supply, +12v charge output & -12V earth lead.
Later alternators have fewer connectors, the modern 17ACR needs only the warning light & +12v charge output, the earth return going through the alternator body.
So the black earth lead & smaller +12v feed from the solenoid are no longer required.
The new alternator arrives.
It seems longer than the 16ACR but some minor mods to the adjustable bracket & ten minutes later it’s aligned and the red light goes out.
To tidy things up and make sure I don’t inadvertently fit the -12v earth lead in place of the +12v charge lead in the future, I stripped the extra wiring out of the loom. It’s all very tight clearance once the luggage bin is installed, but it does fit.
With my perfect 20/20 hindsight I should have done a little bit more research and found that the 16ACR is roughly 1/4" smaller than the 17ACR and hence would have been a better idea. Clearance isn't an issue on the Elan, so I suppose at some point I'll get around to swapping them around. Someday.... maybe.
2016 Update
Well, it only took about 5 years but you really can't rush these jobs you know. And despite 5 years of thinking about it, in the end I didn't swap the 16ACR and 17ACR around.
No, instead I happened to see a dimensional drawing of the Lucas A127 alternator and it struck me as being much smaller than either the 16ACR or 17ACR units. In fact it looked as if Uncle Lucas had designed it just for my Europa, so it seemed rude not to buy one.
Now this isn't an obvious swap. Yes, it fits in place, the pulley wheels align perfectly and it uses the same 3 spade terminal block connector as you can see in this shot, but it's a significantly different beast.
The A127 comes in several varieties but the least powerful has a capacity for 55amps and the most common are the 70amp versions, which is quite a change from the 35amp of the OEM alternator.
Technically the wiring is designed for 35amps, the Ammeter is a 30-0-30 range and hence fitting something with 70amp capacity looks complete madness.
And it probably is, but as you've seen by now, just because something looks crazy doesn't mean I won't give it a shot....
Lucas A127 Alternator
My debatable logic was that I've rarely seen a charge rate over 10amps and it would appear that an alternator supplies sufficient current to satisfy demand from the immediate electrical load plus charging the battery. The electrical load from the car hasn't changed and the 35amp alternator never actually charged at 35amps because if it had done, it would be off-scale on the ammeter.
And I think even I would have noticed that. Maybe theory and practice aren't necessarily the same deal.
So this is early days and careful monitoring is required until I'm happy but so far it's looking hopeful. The maximum charge rate I've seen has been 15-20 amps for seconds after starting. Normally it's just showing a slight +ve charge, just like the 17ACR did.