Regulator for Lucas Alternator - Revised
85jaguar01DATE . . . APRIL, 1985
NUMBER . . . J85/33
MODEL: XJ6 & XJ-S HE
SUBJECT: MODEL A133 ALTERNATOR
KEY POINTS: CHANGE OF REGULATOR FROM 3 LEAD TO 2 LEAD
The regulator for the A133 Lucas alternator has been modified from a positive plate sensed unit with three leads - red, yellow and black to a field voltage sensed unit with only yellow and black leads. This change avoids the milliamp drain on the vehicle battery.
Replacement regulators, P/N AEU 2750, may be either 37666A (3 lead) or 37666B (2 lead).
When a 37666A is supplied for a field voltage sensed application, then the red lead must be connected to the Lucar terminal next to the main output "+" positive stud as illustrated.
At XJ6, VIN-415694, a change was made in the main alternator harness connection. An eyelet in place of the Lucar connectors is used. This connection should be checked for tightness on all vehicles from VIN-415694 to VIN-422892 as advised in mailgram to all Jaguar dealers dated March 25, 1985.