Enduralast Wiring for the '75 R90S

Enduralast Alternator System Wiring Addendum:

For 1974-76 R90/6 and R90S.


My Bikes:  1974 R90/6, 1975 R90S, 1976 R90S.

1.  Diode Board on a ‘75 R90S

•  Diode board has two (2) red positive (+) wires going to: 1) starter solenoid, and 2) starter relay.

•  Red wire to starter solenoid is discarded with diode board.  Red wire to starter relay will be cut at diode board, and later re-connected to starter solenoid (+) post.

2.  Starter Relay, ‘75 R90S

•  Stock wiring:  from starter relay - red & blue go to diode board, black goes to starter solenoid trigger terminal.

•  No “white plug” on older /6 models; blue and black wire are connected to the starter relay.

3.  Wiring Harness from Starter Relay

• Black wire goes to starter solenoid.
• Red wire was attached to diode board.   Ring terminal has been attached to end, will be reconnected to starter positive post.
• Blue wire was connected to diode board, will be reconnected to white wire from Enduralast Regulator

 4.  Red wire from starter relay, was attached at diode board

• Removed female spade terminal

• Attached ring terminal
• Reconnected  to starter solenoid positive (+) post

5.  Stock Wiring Sketch 

• Stock configuration diagram oversimplified to show only wiring altered in installation

• DB - diode board

• SR - starter relay

• SS - starter solenoid

• VR - voltage regulator

6.  Alterations to stock wiring

• DB - diode board

• SS - starter solenoid

• SR - starter relay

• VR - voltage regulator

• Blue wire from SR is cut at DB, will be re-connected to white wire on Enduralast Regulator

• Red wire from SR is cut at DB, install ring terminal an connect to SS positive (+) post

Discard old DB and old VR and discard old red wire from DB to SS, as per Enduralast instructions

7.  Completed Enduralast Wiring

• Blue wire from SR is connected to ERR white wire

• Red wire from SR is connected to SS positive (+) post

• Black wire from SR is reconnected to SS trigger terminal

• All other wiring is connected following Enduralast instructions:

• Red wires from ERR are connected to battery (+) post or to SS (+) post

• Yellow wires from ERR are connected to Enduralast Stator yellow wires

• Black wire from ERR is connected to (+) with key ON, such as coil, as per Enduralast instructions

8.  Photos below show the red wire from ERR passed through grommet with positive (+) battery cable, and is connected to the starter (+) post.

• new battery cables from Euro Motoelectrics (EME).
• new starter from EME
• red wire from ERR is connected to the (+) battery post, or in my case to the (+) post on the starter
• my ERR is mounted in the stock voltage regulator location, red wire to starter (+) post is short length.

9.  The Enduralast Alternator

Regulator Mounting Plate

Alternative Mount for the Enduralast Regulator/Rectifier

1.  Stock voltage regulator location.

·      Regulator removed, frame sanded to bare metal.

2.  Mounting Plate

• Drilled and counter-sunk.
• Pan head screws are used in place of stock socket-head bolts.  
• The regulator is mounted directly to the plate, over these screws.  The screw heads must not impinge on the regulator's underside

 

 3.  Plate mounted to frame.

• I re-used the ground wires that were previously removed with the diode board.

 4.  Eduralast Regulator/Rectifier (ERR) Mounted

• All metal-to-metal contacts sanded;  heat sink compund applied.
• Ground wires attached to back side of mounting plate; bolts through ERR secured to plate.
• ERR is well clear of gas tank and engine case.  Exposed to air stream; should be more than adequate cooling air.

5.  Back side (left side) of mounting plate.

• I used M5 nuts and lock washers on the pan-head screws for secure mounting of plate to frame.

6.   Tank and ERR in place.