Fuse box diagrams: These are out of the 74 manual, so I hope they are the same
First, do ANY dimmer controlled lamps work? Radio? Heater bezel? Gear selector?
If not, then..............................
NOTICE that "cavity one" also refers you to "cavity eight"
That's because the dash lamp circuit is a little trick.
Headlight ONLY that is NOT park, tail, or dash lamps is supplied by a separate power lead.
Tail, park, and dash lamp power comes FROM fuse 8 TO the tail / park/ dash light circuit of the headlight switch , so check that fuse and make sure your park/ tail lamps are working.
Then that power internally in the headlight switch goes to the dash lamp dimmer control, OUT of the control and TO cavity 1 , the instrument lamp fuse. This fuse WILL NOT get power unless............
Tail fuse in cavity one is good and working
Lamp switch is in tail or head "on"
Dimmer control postitioned IE "bright"
Then at this point you should have power TO that fuse in cavity 1
So get that far, then check that you have power on both sides of fuse 1
From fuse 1, power goes OUT to all dimmer controlled lamps.
