Denso Alternator

I'd been having some more issues with my Lucas alternator, so I took it apart and ordered a service kit, which included bushes, bearings, rectifier and regulator.  I started to overhaul the alternator, but during the process I decided that I was not really happy with the situation.  I wasn't convinced that I would not have further problems in the future, so I finally took the plunge and ordered a genuine Denso alternator.

The new alternator is rated at 40 amps, so should be more than sufficient for the modest electrical loads that my Avon can generate.  It weights about 2kg versus the 3kg of the Lucas, so there is a nice weight saving too.

When I removed the Lucas alternator I discovered that the lower mounting bracket had failed.  The front lug had snapped off and it was just the rear lug that was holding the alternator on.  It was lucky that I discovered this in the garage and not at the side of the road!

I took the old lower bracket to the local fabricator/welders.  They removed the old lugs and added strong new fixings for the Denso.

For the alternator tensioner I re-used the old upper bracket and connected it to the alternator with two rod ends and some 8mm threaded rod.

The main output connection is a threaded copper post.  I had a proper battery cable made up that had the correct size ring connector for the alternator on one end and the correct size at the other to connect to the starter motor connection (where the car's main loom terminates the +12v).  This arrange should be much better than the Lucas spade connections, which are prone to arcing.  The cable is more heavy duty than the original Tiger alternator output wire, so this can only help.

More Alternator Woes

Prior to my recent trip to France I noticed that the low battery light was coming on.  On my Acewell dash this is set to come on at 12.5 volts and off again at 13.0 volts.  The alternator warning light extinguished normally after starting so there was no issue with the excitement of the field, there was another cause.

I ordered a replacement set of brushes for my Lucas ACR alternator just in case they were worn.  When I took the back off the alternator and dismantled the brush box I discovered that the wire attaching one of the brushes to the terminal had broken.  I think that the current was being carried by the spring alone, hence the erratic charging of the battery.

Replacement of the brushes is a fairly straightforward task.  I also did a quick health check of the nine diodes with the multimeter.  Then a quick test drive proved that the full 14.2 volts had been restored.  Then it was off to France for the weekend.  All was okay until after arriving in France I noticed the low battery light was illuminated again.  Oh no.  Anyway, long story short I managed to nurse the battery through the weekend and I made it back to the UK without the need for a breakdown truck - phew!

So, alternator out again, back off and then I discovered this:

The red wire had snapped off from its ring terminal.  I suspect that I had trapped the wire when previously replacing the back cover of the alternator.  I soldered a new ring terminal on and carefully refitted the back cover.  Testing proved that the full 14.2 volts had been restored.  Hopefully, there are no more alternator problems.