Get a much louder flasher, I remember large Ford F or C cab trucks in the late 60s early 70s that had flashers that sounded like two tin pans being bashed together, or train wheels going over a joint in the track.
Baring that just wire in a small buzzer and or a large pilot light that sits in the cab that is activated by the signal circuit.
It is just fine gaining years. Howie


1 1955 Chev one ton. 261 engine

3 1962 Chev c-10 261 engine
4 1966 Plymouth VIP 5.7 GenIII Hemi
5 1966 Imperial Crown Coupe 440 engine