WOW! thanks Bill. I have no fuse box. The truck came with no radio (delete plate still there) & what looks like an add on heater with just a toggle switch, so I'd say no box fits your description.
The previous owner said they used to work fine, but they wouldn't light for him when I bought it. I'll check the switch/ fuses first.
The wiring in the truck (what there is of it) is in really good condition compared to other cars I've owned.
I assume the fuse / bi-metal brakers on the switch right, not on the firewall?