Connecting up an alternator Lucas out Bosch in

[Thevak]

The Lucas alternator is dead, is it worth repairing? Ease? Cost? I have a replacement bought as a 105 alternator from ebay but it is a Bosch unit. The confusion I have the Lucas unit had only two connection posts with two wires attached. Guessing one wire was positive wire (brown)and other was generator light indicator wire ( thinner gauge green).

The challenge I have is the Bosch unit has four connection posts so I am confused. Why the extra posts? Am I missing something?

[Neil Choi]

Correct me if I am wrong.

The Bosch one you got seems to be one with an external regulator, so needs to be wired up to one which you don't have.

The Lucas (which I have no knowledge of) will have an internal regulator. 

So if you want to replace your buggered alternator, you can get a Bosch one with an internal regulator which has just the two wires needed as you mentioned, one main (+ve) power (red) wire and the light (green) wire.

Again, I know nothing.

[LukeC]

Later Bosch Alternators (Alfettas) had internal regulators and are very reliable. Most 105s had Bosch externally regulated units so what you have is good... you will just have to buy an external reg and wire it up.

Lucas: "Prince of darkness" 

Years ago up North, my autosparky basically told me to never bring Lucas, Marelli, Paris-Rhone or Ducellier starters and alternators anywhere near his shop unless I was going to supply all the parts... In other words: Don't!

[Thevak]

Say LukeC quickly and it sounds like Lucas so don't go North

Thanks for the info I will investigate both options and let you know how I went. However I would like to stay original so where was the regulator mounted and does anyone have one for sale?

[LukeC]

All depends if you want an original equipment one. Any auto sparky will eith have one or be able to get one. A wecker specialising in 105 may have a good one. Probably best to get the Alt overhauled and the sparky to set the whole thing up.

They are mounted on the inner gaurd behind the battery. Not sure which box it is but you will see one in this image.

[Thevak]

All good, one regulator f rom Monza Motors, a few wires and tinkering and all good! Total cost $110, who says they are expensive to run/repair?