dash harness?
 

What wire is missing from a non gauge dash harness that a gauge harness needs?:bowtie:

I don't know if this is what you are looking for but it may help.
This is a link to GMC Paul’s web site. It is the tips section, which contains the wiring diagrams for both types of dashes.
It has the directions for swapping out the idiot light gauge panel to the gauge panel.


GMC Pauls Tech Tips

Have fun

Thanks:bowtie:

yeah, it is more than just a wire. Don't just plug it in, you'll fry the fuel guage and none of the lights will work properly. It's funny to watch if it is someone else's truck...at least, my neighbor thought so when I did it.

chalk one up for me doin' it too......same thing, fried the fuel guage!