Check the wiring harness, something could have chafed or shorted when the light got crunched, sounds like it could be a ground issue.
Make sure the correct filament is lighting up when the signal is activated.

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1984 300 D runs, interior
1984 300 D light hit in front, RUST, mint/perfect dash, decent interior (see above), parts car
(hate to kill one)
1998 Dodge diesel