Dash light problem

Ok, Folks I have a problem with the dash lights on my 1974 Matador coupe. I replaced all the dash light bulbs when I had the dash apart to replace the speedometer . I replaced the head light switch too. Still no dash lights . Before I worked on the dash I only had a left turn signal light. Now I have both left and right and high beam light plus I believe the brake light. The dash has been molested . It has cheap dual AM/FM /CD player that mostly works badly. And of course the seat belt interlock has been removed. The cars been worked on before to various degrees for one reason or another. I'm thinking the dash light problem is ground some where. The service manual is not giving me a good idea of where the grounds are.
I'm also wondering as I'm more familiar with Javelin and AMXs if it is suppose to have a copper ground in the upper left hand corner of the dash where the instrument cluster goes like on the Javelins and AMXs do , because if so it has none. Bad ground some where is my only idea at the moment . Any one have any thing better. I'm good with electrical but by no means a complete expert . LRDaum

Not sure on Matador but yes, the dash cluster lights share a ground pin - sometimes those get loose from the copper trace. And yes, it's a different feed on the switch. 

Even more fun is the big Javelins - it's a different switch. 
"Instrument lighting" is as said typically a fuse apart from all other lighting (meaning head, tail, brake, etc.)

You can't do any more troubleshooting from in front of the dash. The fact that the turn signal and high beam lights work is a 99% indicator that it's not a ground problem. You'll have to pull the instrument cluster and check to see why you're not getting power to the lighting circuit of the cluster itself. This should not likely be related to the radio as the radio lighting is not fed off the cluster. If your Matador is like my older AMCs then the dash light circuit is fed from the orange wire that starts at the headlight switch connector. Use your test light and see if you have 12 volts at the orange wire terminal of the headlight switch when the headlight switch is on and the dimmer is rotated for full brightness. If you do then it's a short distance over to the cluster connector plug to see if you have 12 volts there on the orange wire terminal. If you do, then you have a bad connection on the IC board itself. Possibly a bad, broken or cracked copper circuit trace coming off at the connection point where the orange wire connects to the cluster. A broken connection on the trace can usually be easily fixed with a soldering iron, some "electronic" solder (60/40 rosin core) and a small length of solid bare copper or buss wire. Even a piece of a paper clip can be used to "jump" a cracked trace on a circuit board.