The combo model does not commonly suffer from intermittent display. What I HAVE run into is a cracked power supply regulator circuit board but that doesn't happen on its own. It is a byproduct of being dropped by the UPS basketball team.
Two totally different things come to mind and are at least a place to start looking. On most models, the display will go out if the radio presets / clock memory circuit is lost. That circuit is tied in with some other system that is always live, typically the interior lights, but it could also be the cigarette lighter or horn circuit. If the fuse is loose in the fuse box terminal, it might cause the problem but the main circuit would act up too. When the radio quits, check the operation of the dome light, horn, and lighter. If they are dead too, we'll know where to start looking.
The other thought is there have been a lot of problems with the ignition switches overheating. The contacts can become arced and pitted and the connector terminals can overheat. The circuit most often affected is the "accessory" circuit which includes power windows, wipers, radio main power, and the heater fan. This is seen most often on minivans when the owners use the heater on "high" very often. I think this circuit includes the instrument cluster gauges so you would have noticed that by now if that circuit was quitting. If the switch itself is the problem, wiggling it often brings things back to life.
One last thing to not overlook is the radio's ground wire. There ain't one! Well, ... There isn't one in the two connectors. There will be a black wire clipped to the back of the radio's case or there will be a big braided strap bolted to the back of the radio. If that is missing or left off, the radio might work through the shielded antenna wire which goes to ground at the antenna base, but that is a very poor ground for powering a radio. You might be able to make the radio act up by wiggling the antenna but if it doesn't act up, it's really not conclusive.
Other than these things, there isn't anything common in the radio itself that will cause these symptoms. Doesn't mean it can't happen, just that these radios are usually pretty reliable. Oh, they CAN develop intermittent FM but that will not affect the AM, display, or the cd and cassette player operation. I just sent one back to Florida for that problem.
A couple of things you can try include a different radio and monitoring the voltages on the two power wires. Any Chrysler radio up to 2001 models will plug in and work although there are a few different mounting ear styles. Different models might exhibit different symptoms if the problem is with the memory circuit but there will still be some noticeable problem. The second thing takes a little longer but you can pull out the radio, then connect jumper wires to the two power wires so you can hook them to a test light while the radio is installed. This is more effective than trying to connect to the fuses because that leaves part of each circuit untested. When the problem occurs, see which of the lights goes out. If both stay on, try using the radio chassis as the ground for the test lights. If the lights go out now, it's a ground wire problem. The two power wires are pink and red. They are right next to each other at one end of the gray connector.
Tuesday, April 20th, 2010 AT 7:39 PM