Look at the flasher. The terminals should be marked, and if there's nothing on the P terminal the pilot light won't work correctly. Sounds like you had the same problem before you changed out the flasher. On the picture, X is the power feed, L is to the turn signal switch input, and P is for the pilot light.
You might also check to be sure the switch is grounded, either thru contact with the steering column or with a separate ground wire.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.