Try this:

http://www.acksfaq.com/diagram_color_86-88_sam.htm

or this:

http://www.acksfaq.com/diagram_color_86-88_sam_no-hitachi.htm

The last time I looked, I believe that the illumination lamps on inside the cluster are wired in parallel - one burns out the rest stay on.

You might want to carefully inspect the flexible "circuit board" on the back of the cluster for broken traces - especially in the bulb traces.

Cluster Removal tip:

Loosen - not remove - the two Torx bolts that hold the steering column in place under the dashboard.  This will lower the "emergency Flasher" switch on top of the steering column assembly enough to allow the dash cluster to pull straight out.

I hope that this helps!

Don't mean to hijack your thread but my dash lights are out also(both cluster and hvac). I thought it was probably the dimmer so I switched my dimmer with a know good dimmer and no luck. I checked power going to the dimmer switch with a test light and no power. I did not see any listing on the fuse panel for the cluster but all fuses look good.

Is there a fusible link some where That I am missing?

If one bulb goes out do they all go out like a Christmas tree? won't help with out power.

Should I just put the dash apart and start chasing wires? 

thanks
jason

So did you actually check for power on each side of each fuse in the fuse block?  If not, do it.
The lights are not like xmas tree lights.  If one goes out, the others will still work.
Since none of the lights are working, I am guessing fuse, open wire, or problem in the multi-function switch (the switch assembly on the steering wheel).
Oh, you did try turning the knob on the dimmer, right?  If it is turned all the way one way it will dim the lights completely out.

Thanks ack and Skyhiranger. It looks like I am an idiot and missed the license fuse when I pulled them all to check them. I did not know that it was the license plate light fuse. I replaced it with a 15amp fuse to check it and it blew the fuse right away. Looks like I will be chasing wires after all.    The color diagram is great and helped me out.


thanks
jason

Thanks ack and Skyhiranger. It looks like I am an idiot and missed the license fuse when I pulled them all to check them. I did not know that it was the license plate light fuse. I replaced it with a 15amp fuse to check it and it blew the fuse right away. Looks like I will be chasing wires after all.    The color diagram is great and helped me out.


thanks
jason

If you have a test light, you don't have to pull all the fuses to check them.  Just touch each side of the fuse with the test light and make sure it lights up (some fuses are only hot with the ignition switch in the run position).  You can also do the same test with a multimeter, but it isn't quite as easy.
What you can do to troubleshoot is to unplug everything that the fuse provides power to.  Then put in a new fuse, then start plugging everything back in one thing at a time, checking the fuse after you plug each thing back in.  Then when the fuse blows, you know the last thing you plugged in is where the short is.  So it is either in that component, or the wire that runs to that component.

Fixed. I did not have my test light with me when it blew the fuse. I did have a flash light and pliers, so i just pulled them all. All but one I guess. I won't say how I found the shorted wire but I will say it was 99% stupidity and 1% smoke.

The short was caused by the radio ground wire being plugged into the red/yellow wire from the clock plug. I would like to blame it on the previous owner but I installed the radio. I don't think I would have plugged a ground into a hot wire, I am usually a lot smarter than that. Except that one time with a paperclip and a wall outlet when i was six, lots of sparks! The weird thing is, I was driving at night when it blew the fuse. The headlights had been on for at least ten minutes. It should have blown the fuse or smoked the wire as soon as I flipped the switch. Hmm... It is fixed now, but a light burned out last night. It is probably the RRO parts I have that are causing the problems. 


jason