My dash lights were doing the same thing, but are 6 volt. I found the rheostat part of the light switch was at fault. Simple solution was to take the dash light feed to a lug on the light switch that supplied full voltage to the dash lights. No problems in the past 4 years or so and that includes some pretty long (as in many hours) night drives.

GoodLuck, RonR


RonR


1951 3600 with Clark flatbed, T5, 4.10 rear
1970 340 Duster
1990 5.0 V8 Miata (1990 Mustang Gt Drivetrain)
1964 CJ5