Hi, I have an issue on my 66 c10. When i step on the brake, my RH turn indicator light comes on, the brake lights come on in the back as well as the RH front turn indicator. Where is the best place to start looking. My dad bought this truck new and it is all original, wiring harness, switches and there is no trailer plug or wire splicings.

Thanks,
Pat

1946 PW Grain truck, 1966 C10 long stepside, 1972 C20 Custom Camper Big Block, 1975 C10 Silverado OE big block.