Alternator wiring - only one output?

[RichardS]

I have fitted a 45 amp Lucas ACR replacement alternator.

I've updated the wiring using the wiring diagram in the technical section with 8 fuses.

I've connected the alternator up as in the diagram which show a white [14] running from the alternator to fuse 6 which is the switched ignition circuit. I've connected this white [14] to one of the large spade terminals on the alternator, the other large spade terminal connects to the battey + wiring and I've run the small spade terminal to the ignition warning light.

But .... wired this way the ignition warning light comes on when the ignition switch is off, and the indicators also work despite the ignition being off - ie it seems the "switched" ignition circuit is being bypassed.. I think the 2 large terminals on the alternator are common so that 12v runs down the white [14] from the other large terminal that connects to the battery + circuit. Disconnect the white wire and all the electrics work fine and the ignition light only comes on when the ignition is switched on.

Is the additional white wire needed? I understand that the alternator needs 12v through the warning lamp circuit to get going. As far as I can see the white wire is pumping 12 volts into the switched ignition circuit but 12v is already being provided down the main output cable to the battery circuit.

Thanks

Richard

[Frank Howard]

Richard,

From you description, it appears that you have three wires. The first one is white, the second one is white and the third one is unknown. Did the alternator come with a 3 wire pigtail harness? If so, what are the colors of these three wires?

[RichardS]

Frank

I've wired in the alternator as in the wiring diagram http://www.lotuselan.net/uploads/elan_m ... wiring.pdf

White [14] from large spade terminal to fuse 6

Brown/yellow [14] from small alternator spade terminal to ignition warning

Brown/White [84] from other large spade terminal to battery 12v +

The connection to the alternator spades is with a standard alternator plug.

Any clearer?!

Richard

[neilsjuke]

You do not need the wire to the fuse box this would have been for a old type ACR the small terminal is w/l the large pair joined inside so output make sure you have 45 amp + cabel
Neil

[Frank Howard]

I have never seen this diagram before. I studied it and concluded that you have wired it accordingly. I would look at the connection to the alternator and check to confirm that the white wire actually connects to the terminal marked "IG" on the alternator and the brown/white wire actually connects to the terminal marked "B" on the alternator.

White [14] from large spade terminal to fuse 6...
Brown/White [84] from other large spade terminal to battery 12v +

I think you should switch the two above. White [14] should go from large spade terminal to battery 12v +. Brown/White [84] should go from other large spade terminal to fuse 6. Let us know if this works or if we should stick our fingers in our ears and wait for the explosion.

[alan71]

Richard,
Your alternator may look like a 3 terminal one as shown in the wiring diagram but as Neil says the 2 large terminals are connected internally, so it is really a 2 terminal type.
Just remove the wire from the large terminal to the fuse and you should be OK.

Alan

[RichardS]

Thanks everyone - confirms my thoughts and that my conclusions were concurred with! The main brown/white cable is a nice thick cable!. The "extra" thin white was pumping 12v into the switched ignition circuit and causing the problem. I will leave it disconnected.

Richard