After some exhaustive work I finally managed to pull the instrument panel out of the dashboard without removing the dashboard itself. This wasn’t easy but the good folks at brickboards.com assured me it was possible and they were right. First I unscrewed the speedo cable and then pulled the wires out of the jacks on the back. Once I’d done this I wish I’d labelled the jacks but they look individualized enough that maybe it won’t be such a pain in the ass reconnecting them when I’m done? We’ll see.

I started by setting the whole thing on my desk:

I snapped some photos of the back before I started removing screws:

The little can on the bottom center with the 3 wires going into it is the voltage stabilizer.

This is where the speedo cable screws in:

Here’s some other photos of the front with the gauges portion separated from the speedometer cylinder. Separating these parts is a series of screws and it is very easy so I won’t bother going into the details. If you managed to get the instrument panel this far you can figure out how to disassemble it Just make sure not to lose any of those tiny screws!

OK. Now taking the voltage stabilizer off is a matter of carefully disconnecting the 3 wires that attach to it, which is easy – they are all secured by male/female crimp connectors. The voltage stabilizer is attached to the instrument panel by two metal tongs on the stabilizer that clip around a little rubber nub that is secured to the back of the instrument panel. Pictured here:

Next was the toughest part – I had to pry the lip back from the backplate of the stabilizer so that I could open it up. This I did with some careful work using a pair of needlenose pliers. I didn’t want to destroy the stabilizer housing. When I was done and opened it up it looks like this:

This is as far as I’ve gotten with the voltage stabilizer. I purchased a 5V regulator and a 0.01uF capacitor from Radio Shack for $3 and I will soon solder it to the proper points and begin testing. Hopefully this fixes my gauge problem and will provide a more reliable stabilizer for my nearly 40 year old instrument panel!