Lights Switch Operation

[wchevron]

When I bought my '77 a few months back the headlights and dash lights didn't work. Been doing some other work to it and had a guy from work (former mechanic) take a look. Just got it back today and headlights are working. When I pull the Lights knob out, the gauge/dash lights were not coming on. Thought maybe they were all the way dimmed. Turned the knob switch counter clockwise and the gauge lights started to brighten. When I push the Lights knob in, the dash lights don't turn off, but the headlights do. Have to turn the knob all the way clockwise until i feel a click, then the lights go out. Is this normal. I figured when I pulled the knob out, to turn the running or headlights on, the dash/interior lights would come on?

 

[peesalot]

something is hooked up wrong or the guts of the switch are not right.

 

[Engineer8000]

Based on the schematic, this is not correct. The dash lights should be off when the knob is fully pushed in.

(courtesy of Mr. @Coolerman)

 

[Living in the Past]

Tail lights, parking lights, side lights, license plate light should all work with the interior lights in both positions other than off. The connection to ties these all together is inside the the switch. If the parking lights and rest with off the switch as they should then something wrong inside the switch terminal T ties everything but the headlights together. Do the headlights only work with the switch pulled all the way out? Do the other lights work with the middle and all the way out positions?

 

[wchevron]

With the switch pulled to the middle position, front and rear running lights are on. Pulled all the way out, the headlights come on. If I turn the knob counterclockwise, the dash lights come on and will stay on regardless of which position the knob is in. Off, middle, all the way out. Unfortunately when I bought the truck, the lights weren't working at all so not sure if my guy wired something wrong or bad switch light you mention.

 

[Living in the Past]

Unfortunately the connection for the interior lights and the other non headlights are a connection in the switch. It acts like the rheostat wire was moved from T terminal in the switch to one of the B terminals inside the switch. Next step would be to pull the headlight fuse and tail light fuse to determine which one other neither. Some where else doesn't made any sense since the rheostat is inside the switch. It's possible to rebuild the switch. But easier to just replace it.

Since these are NLA I would pull the switch from the dash and inspect for any possible hacks from a PO. Would take some work to run a separate power source to the interior lights. Moving the wire to the rheostat internally would be the better way to do it. But POs do crazy things. I was running a 78 light switch in my 68 for a long time. I managed to do this with moving wires around in the plug. Went back later to the original switch but still need to clean up the wiring.

 

[wchevron]

I actually have a spare switch. Was in a box with some other misc items when I bought the truck. I'll swap it out and see if it works. Wonder if the PO had the same issue and never got around to swapping the switch. Considering none of the lights worked when I bought it, its probably not too far off.

 

[wchevron]

Had some time this winter to play around with this. Took my spare light switch apart and cleaned all the terminals. Figured I could use the spare as my new light switch. Didn’t find anything broken other than a little dirty, looked good. Wired it up this morning. All the lights are working correctly but having thr same issue as the original light switch. Pull lnob out once and no interior lights. Running lights come on. 2nd pull and headlight come on. Need to turn the knob to get the dash lights on. I did notice on this switch the dash lights only come on when the copper spinning piece connects with solid copper terminal piece. When the copper spinning piece is rotated along the coiled wire, no dash lights.
This is opposite of my original light switch. That switch won’t turn the dash lights on unless thr knob is turned also. As soon as the spinning piece touches the coiled wire the dash lights turn on. Only way to turn them off is to turn thr spinning piece to where it is resting on thr plastic housing and not making contact with the coiled wire.
Not a big issue either way but I’m scratching my head trying to figure it out

 

[charliemeyer007]

On my 72 out one click is the marker/running lights. Out two is the headlights. Hi/low is foot switch on the floor. Rotating the knob is instrument light - goes from off threw dim to full on. Darth is on/off by switch near by. B pillar on my 76 top is a switch on the light.

I haven't had mine apart since the 80's. I seem to recall a rheostat controlling the dim and a small tab that lifts the contact for off.

 

[wchevron]

Mine is a '77. With my original switch, dash only turns off when I'm on the small tab you mention. Doesn't matter what point the knob pull is at. Knob all the way in, turn the knob and lights. First pull, if knob not turned no lights, 2nd pull if knob not turned no lights. Soon as I turn the knob off the small tab, lights. When on the rheostat (coiled wire) I get no dimming just constant light. (I did install led lights in the gauge cluster and center dash and heater lights so that might be my dimming issue.)


With the spare switch, no dash lights along the rheostat, only when I hit the solid copper contactor at the full dash light point. Doesn't matter if the knob is pushed in all the or pull out to first setting or second.