Well, that was stupid! I read 40, not 49! Edited: Should be a circuit breaker and fuse. I would start with the light switch and see if there is power on the dash lights terminal.
Does your headlight switch dim the dash lights. if so make sure it is not in the wrong position. Check the harness and look for loose connections to the dash lights, especially at the light switch.
Rotate the knob into different positions when your checking for power. Some older switches have a “sweet spot” for them to come on. They’re not very bright so you may have to have it almost dark to see them come on. Have they worked in the past? There are a lot of threads on here for solutions to the dim dash lights.Any pics of your car? Love shoeboxes!.... Mark
49 headlight switch does not have a dimmer feature.
There is a toggle switch on the left of the steering wheel that turns the dash lights of or on once they have been turned on by the headlight swiitch.
Over the years that toggle switch has been removed but it was standard on the 49. My 49 convertible has the switch and I have seen other 49’s with the switch still in place.
If you are referring to the speedometer cluster...the lights may be on but you just can't see them. Very common on the '49-'50 shoebox Fords. I believe Ford referred to it as the "blacklight" system (or something like that). There are four (4) dark "filters" that covers the bulbs in the cluster. Over time...the light will no longer penetrate the filters...thus at night you can't read the speedometer or the gauges.
I'm not a shoebox guy! But, believe it is on the backside of the instrument panel, part # 12258 on the routing diagram. There is a lot of good information and wiring diagrams at VanPelt's site.