i have read every blog i can find on dashboard lights not working, including videos, i even have the large paper schematic for 1974 f100 written by aliens, the ones that live inside the moon. i can not determine why i have no connectivity to 3 wires.
i have a new headlight switch, have tried 3 just in case found new old stock all work the same, and the steering column wiring harness is new to the truck, not by me. i managed to fix the horn and horn bar. i have the 2 blue lights behind the speedometer, light at headlight switch and dome light work but, the 4 lights that illuminate the gauges do not have current. the printed circuit on the cluster back has connectivity. 2 of the cluster lights work when i turn on signal lights or hazards but dont work any other time.

i managed to find the 3 wires that should provide current to the 4 lights.
white with blue stripe, white with red stripe and a small gauge purple wire.
i pulled the connector under the dash apart to check connectivity, part A connects to steering column, part B connects to fuse box and other things.
there is no connectivity between part A and B for the white with red stripe or the white with blue stripe but part B does show connectivity for the white with red stripe to the unit, call it part C, that plugs into the back of the cluster. there is a purple wire on part C and i can find no correlating purple wire that i can test, (it is not the one that is connected to the ignition) there is connectivity between the top of steering column wiring and part A, so no short indicated.

on part C where bk/bk-gr is indicated i have black/purple, the purple is heavier gauge than the other purple wire next to the white with red stripe and seems to connect to ignition switch where a black and purple wire are combined.
i show connectivity between the combined wires on ignition and the black/purple on part C.

i do not see an ignition switch color combo like the one on my truck in the schematics.

i have checked all the wire colors with their respective locations on part A and B, with the exception of the black/purple wire connection on part C all wires are as indicated in schematics.

 

Its not clear to me what your problem is.

Do you have gauges for oil, temp, fuel & alt? Or do you have warning lights for oil & alt?

What lights do not work? Turn signal, brake, high beam, 2 cluster illumination, oil & alt warning lights?

I am not clear on what you mean by "the 4 lights that illuminate the gauges" .

 

here is link to schematics 1973-1979 Ford Truck Wiring Diagrams & Schematics - FORDification.net i am looking at page 2 and 3
wiring_master74master_2of8.jpg
at bottom of page
block c-260 14481 with gauges

this block shows all color of wires in respective slots, where bk/bk with green strip is indicated i have a bk and a purple wire combined.

none of the ignition modules on this page match mine, mine has 5 connections in the harness

wiring_master74_30f8.jpg
at bottom of page
block c-305 shows steering column wiring harness, all my wires are as indicated in this diagram

i rechecked printed circuit and there is connectivity to all the bulbs

the blue lights come on when i turn on headlights
the 2 light clusters on either side of the blue lights do not come on but, the 2 closest on the left and right of the blue light flash for signal and for hazard

all gauges work

 

The light on the far left, going from memory, is a brake light. It comes on when you lose brake pressure like when a rusted line blows, or when the parking brake is on. A lot of the time the connector is popped off the switch under the hood to turn the light off, or the switch on the parking brake is bad.

Next light to the right should flash when the left turn signal is on, or when the 4 way flashers are on.

Next two lights, in blue, are the cluster illumination lights.

Next to the right should flash when the right turn signal is on, or when the 4 way flashers are on.

Far right light should come on when the high beam headlights are on.


There are just two lights to illuminate the gauge cluster, the blue ones in your picture.

 

okay, as i understand your answer. the lights that "i think should be coming on" are lights for a different purpose that illuminate when that purpose is required. that would be awesome and end days of frustration and confusion. that is awesome, thanks so much.

 

Hight beam indicator light is above the speedo. Light furthest to the right (right of the right indicator light) is the seat belt light.

 

The high beam moved to above the speedo in 76 or 77. Before that the high beam was on the right, no seat belt light.

 

I kinda wondered about that.

 

thanks for the info, i finally have the dash lights and other electrical issues resolved, attempting to install radio now

 

not needed because you have it sorted, but I notice you have replaced the bulbs with LEDs - they only light when the current polarity is correct so sometimes a dead LED is just inserted wrong and can be cured by reinserting the bulb 180 degrees differently.