Fule/Oil Gauge Question -- Light and Extra Wires

[Scbrindley]

My dad just purchased a '87 Targa and we are in the process of sorting through a few things.

One being the lack of lights on the fuel/oil level gauge. The gauge works fine and I checked the light, it's not a burnt out bulb.

After pulling the gauge I found two unplugged wires (in picture) and a prong on the back of the gauge (appears to be a ground) that doesn't have a wire connected.

Does anything here look odd? Am I missing something extremely obvious to make the lights work?

I'd pull the gauge from my '89 and compare but it's currently at Ed Mayo's shop for some engine work....

Thanks in advance for your help!

SB

[gerakroo]

I checked this at a other 87 and the same prong had no connector as well.
Do you have a rear wiper and is it still working ?
The smaller female terminals look like the ones on the rear wiper switch ?

You can measure the voltage with a simple voltmeter, brown is ground, red/black is positive. Black-blue is from the dashboard lighting.