Shift Console Illumination Facts
Like many others, I have intermittent/no illumination of the shifter console. Being the Internet, there's also a lot of incorrect info about how this lighting is done, some of it being confusion between WJ and other models. Here's what's really going on.
The illumination is done with electroluminescence. The emitting material is printed on a mylar sheet. Two connector sockets are crimped onto the sheet, and they plug into the power supply which sits in a pocket underneath. The power supply gets +12V dash power in on the black and blue wires. The protruding pins at the top will develop around 450VAC at 120Hz. EL is based on high voltage at almost no current, so you might get a poke but it can't kill you.
The most likely failures are:
1. Crimp failure - the connector tabs stop making good contact with the material. I have heard these may be reinforced with soldering but have not done this myself. Beware of what heat the sheet can tolerate. If your DMM shows voltage at the supply pins, check the crimps closely.
2. Supply failure - if the 12V is present at the input wires but no high voltage is read the supply needs replacement. The best thing is get a shift assembly from the junkyard - no one sells the supply by itself. Its also pretty hard to pry out the pocket.
3. Supply startup probelms - intermittent operation can be tied to this. The supply is essentially an oscillator with a step-up transformer. Sometimes the oscillator just doesn't want to get going. Sometimes adjusting the load can fix this, like putting a 10Mohm resistor or 100pF cap across the output. I will be trying this with mine next time I'm motivated to pull the console apart.
I have given thought to making a replacement sheet using LEDs, but again there's more work to be done there.