These trucks are great little workhorses and there is quite a following for them. Unfortunately, certain parts are almost impossible or too expensive to get. Case in point is this stupid instrument dimmer switch. This design is notorious for bad rheostats. This is the third one in my truck and I installed it back in 2001 when they were still relatively cheap and available. When they break, the instrument lights go out.
Nowadays you have to look long and hard to find one -- a local used parts guy wanted $115 for this thing -- LOL. Good for him if he can get it. Here is the rheostat on the old dimmer --
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0336Medium-1.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0335Medium-1.jpg)
Most owners in this situation just by-pass the rheostat by placing a jumper wire in the connector and getting full power to the instrument cluster lights all the time. A good solution, but for 25 year old dash lights, this solution will shorten the life of the lights.
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0334Medium-1.jpg)
Although the correct year/model switch isn't easy to come by, there are plenty of OEM Mazda dimmers available for less than $10. I chose a Mazda 626 switch that was used during the late 80's and early 90's. Smaller profile, but the terminal design is basically the same.
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0337Medium.jpg)
The 626 terminal are much smaller, so rather than cut off the old connector, I modded the 626 switch with new terminals to fit the old connector.
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0338Medium.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0339Medium.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0340Medium.jpg)
Quick test and it works like new --
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/PICT0341Medium.jpg)
The dash will need to be trimmed a bit, but it's a good fit and works great. I need to do some other work on the speedo before I can button it all up again, but for $10, this is a good solution for an increasingly expensive fix.