Big Red Speedo Light question

[ps2fixer]

Can you add a couple photos of the socket? Maybe we can spot something.

Also, you happen to have a multi meter and know the basics on how to use it?

[Jd110]

It plugs into the main harness, anyway. You had a hunch it is a ground issue and there are only a couple connections to check. It shouldn’t be difficult to check the base of the socket. You may have to cut the loom where it is heat crimped, to get the boot to slide down enough to access that. See the picture above-it’s not a great connection from the go. Again, check that green wire at the back of socket. Good luck!

[MFW]

So here are some pictures I took.
Picture #1 is of the wires going into the socket.
Picture #2 is of the light switch on but the light isn't working.
Picture #3 is of the light switch on and the socket touching the speedometer housing.

[MFW]

Sorry, trying not to beat a dead horse here. I went through all the connections again and cleaned them again. They started off clean since its been in the high desert its whole life there is zero rust on anything.

[ps2fixer]

Interesting situation, sounds like a bad ground connection. Clearly the brown wire has good connection. I think the easiest test would be to disconnect the green wire only and ground the wire and see if the bulb comes on. If not then I'd suspect the wire is broken internally in the insulation. If it works, then I think we'd need to further test your grounding, or maybe something isn't hooked together right.

Do you have a multi meter and a basic understanding how to use it?

[MFW]

I took the harness that comes with the speedometer kit which is an extension to the main harness out and plugged it directly to the harness. Same issue. I might just get a small wire and have it tucked into the grommet and overlap it so it touches the house so it will ground and work correctly.

[ps2fixer]

Since it's just bullet terminals, try to plug it into the tail lgiht socket (green to green, brown to brown). If the tail light works and the bulb socket doesn't power the bulb, the green wire is bad. If it works, there's another electrical gremlin going on or hooked up incorrectly (photos of what it connects to wouldn't hurt).

[Jd110]

With-in the speedometer light harness, there are two green wires connected together, underneath the plastic loom.

[MFW]

I will take a look at it again. Thanks guys