Dash lights problem

[Krex]

Just installed a painless harness in my k20 lwb

I need some help with dash/instrument panel lights not working?

All other lights wiring works as designed. I have not used quite a bit of the harness like power windows, cruise, heater, dome, courtesy lights, I don't know if this could be my problem.

I also plugged in a new headlight switch, first attempt headlights work, tail lights work, hi and lows work, no dash light, so I turned the dimmer on the switch it shorted and small electric smoke and a saw a quick flame. And blew my horn fuse which is connected to the tails,

Using the same headlight switch I replaced the fuse and the horn fuse blew.

I decide not to use the new switch again, replace the fuse got my old headlight oem switch and headlights and tail lights work and don't blew horn fuse.

Any tips, advise, trouble shooting help, tests, etc?

I was thinking about just going to get a another new headlight switch, but I think it may be more than that.

Thanks again for the help -Rex

[Krex]

Anyone have an idea ?

[Krex]

Let me know if someone needs more information

[_Ogre]

it would help to know what year your working on
did you wire the dash lights into the headlight switch?

[Mike C]

Dash lights run through the rheostat on the headlight switch. My experience is when they quit it's either broken or dirty but with the new harness it may be that circuit was missed? And I answered almost this same question on the main board right before this. LOL

[Krex]

How do you mean the circuit was missed?

In the headlight switch I thought it was the grey wire

Year is 1972

[ray_mcavoy]

I don't if the Painless harness you're using has the same configuration & wire colors as the stock GM wiring or not.

But if it does, an orange wire (protected by the tail light fuse) feeds power to the parking & tail light portion of the headlight switch. When the switch is turned on, power from the parking & tail light circuit is fed into the rheostat via an internal connection in the headlight switch. The output from the rheostat runs through a green wire that leads to a second fuse (usually marked INST LPS or similar). Then a gray wire runs from that fuse to the instrument panel lights.

[VetteVet]

There are still some unanswered questions. Does this painless harness come with a new style fuse panel and where is this horn fuse? There is no horn fuse on the stock 72 harness fuse panel.

Here is a diagram of the dash lights on the 72. If you can follow the gray wire from the fuse panel and the orange wire to the headlight switch you will see the path of the lights as Ray described them. There is a ground terminal on the headlight switch that turns on the dome light when the knob is rotated all the way to the right or clockwise I believe. If your harness doesn't match the headlight switch, then that may be where your short occurred.





This one shows the green wire from the switch which runs to the fuse panel after it gets power from the orange wire that feeds the tailights.