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Discussion Starter #1
Shop replaced original alternator with remanufactured OEM Lucas alternator - but the new alternator is not charging the battery. Advanced Auto test shows 0 voltage from the alternator, battery warning light is on and new battery, which tests fine, must be recharged after driving.

It is possible than an inexperienced mechanic incorrectly connected the wires.

There are a total of 4 connections: 2 bolted connections: 1 large brown wire and 1 small brown/yellow wire, and 2 blade type connections: 1 blade with green wire spliced to blue wire and 1 blade with two white wires, one of which is spliced to a blue wire.

If anyone has the OEM or remanufactured Lucas alternator on your truck, I’d be grateful for a photo of the correct positions of the 4 wire connections.

1992 RRC
 

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There is only really two connections: power and warning light. The power is often on two wires, big and small. The big cable carries the current, while the small cable is meant to provide battery voltage if the alternator has that feature. The idea being that the alternator regulates its voltage based on what it can sense and if there is a high load there will be a voltage drop and thus too low a voltage reached the battery and it will not charge right. Running a separate cable directly to the battery which only provides the reference voltage solves this issue. Anyway most likely you have both these plus wires together on the larger stud. The spade is to mount a noise suppression condenser.

I don't really want to spoil your party, but I have struggled with Lucas alternators. I replaced a bad old one with a refurbished Lucas, which barely put out any amps, fluctuating voltage up and down. I then replaced it with a rebuild Lucas which put out no power at all. I then bought a rebuild Bosch alternator, which was just a Lucas with a Bosch sticker on it, but out 12.1V on the terminal.

In the end I bought a real 110A Bosch (VW I think) alternator with a special pulley (my 83 has a V-belt) fitted that. It measures 14V with 60A of max load. Perfect, never looked back.

A real Bosch alternator has the white two prong voltage regulator screwed in the back.

Good luck.

https://www.ebay.com/itm/Land-Rover-Range-Rover-Classic-Alternator-Generator-BOSCH-110Amp-Replaces-LUCAS/352323745001?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
 

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Discussion Starter #3
JS5D, thanks so much for your quick reply and for sharing your experience with the Lucas alternators. Will return the remanufactured Lucas and appreciate your suggestion regarding the genuine Bosch.
 
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