If you have the battery in place even if it is low on charge, jump starting and then running the lights should not damage the alt/reg.
If you have no battery in the car when you jump start it, the alt should not start to generate power, the only way it could would be if there was any residual magnetism in the alt.
I have disconnected the alt on a stationary engine, used jumper leads to start it & run for days without a battery, no electrics.

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving