Dash lighting issue

[adamfeber]

1973 dart sport dash lights are not working. I'll start with the fuse and work my way up. What fuse in the block is supposed to be for the instrument panel? The far passenger side fuse in the block has no juice on either end...

 

[67Dart273]

The instrument fuse is a "trick."

The headlight switch gets power from TWO sources

ONLY headlights are one source which is not fused. The headlight switch has a built in breaker

A SECOND power source TO the switch comes from the TAIL circuit fuse. This powers park, tail, and INSTRUMENT lights.

After power goes through the light switch, and through the dimmer control, it goes OUT to the instrument fuse

So in other words the tail circuit fuse must be good and that circuit working

The light switch must be in either park or headlight position

Only then will you get power to the instrument fuse.

And of course the fuse must be good.

 

[Bad Sport]

I had no dash lights for a bit, I know I tried messing with the switch several times and nothing. I also chased things down and could find no other issues.

One day last fall while sitting in the car I randomly decided to turn on the lights again and with a slight turn of the switch my lights came on.

It turns out if I turn the switch just a tad too far toward full bright they go out. Probably a dirty switch in my case.

Just throwing it out there.

 

[67Dart273]

..........and wiggle the 'ell out of the knob dimmer control left/ right. These get "bad spots"

 

[Bad Sport]

..........and wiggle the 'ell out of the knob dimmer control left/ right. These get "bad spots"

LMAO, ain't that the truth, had me pullin' my hair out.

 

[jdsduster]

if i remember az sell new ones fairly cheap

 

[TrailBeast]

Under 20 bucks at Autozone.

 

[adamfeber]

So I am assuming the fuse that the big arrow is pointing to (see pic) has to do with the instrument lighting because the wires going out are orange which I believe is instrument lighting color, right?

The problem is, it does not have any juice going into the fuse so obviously there is no juice going out. What is the source of this fuse wiring coming from?

Also, see the two open fuses on the block - far right in pic. These are both empty - are these supposed to be blank and left for accessories? I tied into one for my guages and just put a 5 amp inline fuse instead of using the fuse block.

 

[adamfeber]

..........and wiggle the 'ell out of the knob dimmer control left/ right. These get "bad spots"

FYI, done with no luck. The switch was working fine previously unless it just decided to die on me.

 

[adamfeber]

The instrument fuse is a "trick."

The headlight switch gets power from TWO sources

ONLY headlights are one source which is not fused. The headlight switch has a built in breaker

A SECOND power source TO the switch comes from the TAIL circuit fuse. This powers park, tail, and INSTRUMENT lights.

After power goes through the light switch, and through the dimmer control, it goes OUT to the instrument fuse

So in other words the tail circuit fuse must be good and that circuit working

The light switch must be in either park or headlight position

Only then will you get power to the instrument fuse.

And of course the fuse must be good.

@67dart273 - see my comment above. The instrument fuse does not have juice going into it - even when light switch is in any position. Headlights work fine.

When you say:

After power goes through the light switch, and through the dimmer control, it goes OUT to the instrument fuse

So the power goes through the light switch, and then OUT to the instrument fuse. So if I pull the dash and have power going into the switch and none coming out, it would mean a bad switch.

Will the power going into the switch be constant?

 

[67Dart273]

Power into the switch will only be there if the tail fuse is good. Be sure to check the diagram as there should be TWO hots to the switch, one for head and one for tail/ park / dash.


Power goes to the switch, through the switch THROUGH THE DIMMER CONTROL and then to the fuse. Usually the wire from the dimmer output to the inst. fuse is tan. "Always," the wires leaving the fuse are orange......These are the feeds to all dimmer controlled dash lamps.

So if the tail lamps work, check the dimmer rheostat on the switch. This is a common failure. 'S why I say wiggle the 'ell out of the dimmer, as they get "bad" spots, IE corroded, dirty, etc.