Pre 1970 vs. Post 1970 Alternators / Systems -- SOLVED IT - See Post # 12

RPMagoo said

I'm still dealing with electrical problems, on My 65 Valiant. --- I plan to switch to a post 1970, flat back, alternator, with a external, solid state, voltage regulator. Since the alternator will have 2 field wires, I've been told that I can simply connect each of the 2 wires to the field posts, on the alternator, (1 wire is already in the wiring harness, from the old set-up) then connect the 2 wires together, at a point prior to the connector at the voltage regulator. The regulator is a VR706 type (Ign. & fld. connectors only). -- My questions are -- (1) Is this true ? -- (2) Will this cause any problems ? -- (3) Will this allow Me to take full advantage ( steadier lights etc.) of the switch to the newer alternator. -- I assume that the new alternator will be 78 or 80 amps vs. 60 amp on the old, pre 70, 1 field unit.

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Hi,

The stock 65 Valiant alternator was something like a 35 amp unit. What you are calling a "flat back" alternator is called a "square back" and is a 1972 and up type usually rated at 60 amps. Unless a rebuilder turned it into something else which is entirely likely today.

You will need a new connector to fit your new electronic type regulator. You would connect the existing green wire to one field connection on the alternator and the other end of the green wire to the green wire on the new regulator connector. The blue wire on the regulator connector goes to the RUN side of the ignition switch, usually a blue wire on one side of the ballast resistor. You will also need to run a new blue wire from this same point to the second field connection on the alternator.

The square back alternator will produce more output at engine idle that the original alternator but, don't expect it to be like a modern car. The lights are still likely to dim at idle.