Stereo wiring problem

"It got power for a split second. Turned off the engine, turned it back on, same thing".

What does, "same thing" mean? It powered up for a fraction of a second or it is totally dead?

The radio will work okay if you have the two power wires reversed, but it will lose the station preset memory if they are turned around. Check for twelve volts on those two power wires. One must have twelve volts all the time. The other one will only have it when the ignition switch is turned on. If the fuse for the memory circuit is blown, the interior lights will also not be working. If the switched circuit is bad, most commonly from burned terminals at the ignition switch connector, the heater fan and power windows will also not work.

If they are okay, we continue on with other tests. The typical problems on these cars start with one of the power wires not working. The biggest issue is when people go looking for the ground wire in the two plugs. There is not one. All of these radios will have either a braided strap or a black wire bolted to the back of the radio. That can be used with the replacement radio. If it is not used, the radio may get a ground through the outer braided shield of the antenna cable, but that is a very poor ground and will lead to intermittent operation.

People who are a little more knowledgeable about electrical circuits will go looking for a ground wire in the two plugs, and with resistance readings, they will find two that have such low resistance, they must be ground wires. In fact, they read so low because you are reading through multiple light bulbs, then to ground. If either of those are used for the new radio's ground, a fuse will blow and you will have a not working lighting circuit. One of those circuits is the tail light circuit. That one tells the original radio's display to dim when the head lights are turned on. The second wire is tied to the dash lights. That one tells the display how much to dim.

You also have to determine if your car has a factory amplifier. If it does, it will have to be bypassed. It will work with aftermarket radios but the tone response will not sound right. Unlike radios and amps in other car brands that must be matched, Chrysler amps do not increased volume or power. They are used strictly for tone conditioning for the shape of the body. Any Chrysler radio will work with or without an amp, but if the right radio model is not used, you will have too much or too little bass. If there is an amplifier, it will be bolted to the floor under the passenger front seat.

If the original plugs are still in the car, a much better alternative is to get a CD/cassette combo radio from a salvage yard. Those were built by Mitsubishi for Chrysler, and are very high quality. The CD-only models were built by Alpine. Those have more problems, so I always sell the combo units for upgrades, even when the customer does not have cassettes.