Speedometer/Odometer Lights not working
 

Just finished repairing the gear on the tach in my '88 which crumbled. I carefully marked all wires and reinstalled it then did a test drive last night. The odometer is now working but ALL three lights are out...WTH did I do wrong? I made sure the lights all went back in exactly the same holes they came out of but I think two are interchangable so that does not seem to be the cause.
Also, I now noticed what appears to be an unused brown/white wire with a female blade connector that is accessible in the hole where the speedometer goes but I'm 99.99% I don't recall it being hooked up to the speedo and I don't recall removing it, I think it may be a red herring for this problem but I am curious as to it's function.
TIA

I believe the wire to the instruments is blue with black stripe. Are the lights on the other instruments working? Is the knob on the slight switch turned so the dash lights are on brightest?

Yes, all other lights in dash are working perfectly. Only the speedo/odometer lights are out. It has 3 lights, 2 for guage/dial illumination and the third for the parking lights and none of those three appear to be working. Very confusing...

Note, I am unfamiliar with the 88 but on earlier cars the parking light is on a separate circuit from the instrument lights as it lights with the first pull of the switch, but goes out when the switch is fully pulled while the instrument lights remain on. From what you describe, something is amiss somewhere along the harness from the speedo to the light switch. Pull the speedo and see if you can follow the wires from the lights. Possibly there is a connector that has come unplugged. It may take some acrobatics looking under the dash or even a small mirror inserted into the tach hole.

The instrument lights are all wired in series so you should be getting power to the speedo lights if the others are on unless there is a break in the wire. Have you checked the sockets with a voltmeter? Is there any voltage from any sockets? How about the speedo body--is it grounded properly? Maybe the ground wire has been disconnected. Checking for power at the sockets with a trouble light or voltmeter will tell if there is a break in the wiring.

LJ,
I think you have got me in the right direction. I can get the lights to come on IF I ground the socket to a ground point inside the dash. I must have somehow done something to the ground in the case. Not really sure how I messed that up but at least I'm in the right direction. Thanks!

That's good news! Much easier to fix a ground problem than to track down an open circuit. Keep us posted.