I'm thinking the "flickering" of his dash lights can describe more than one type of event.
In chryslers, many dashboards will flicker when the ecu is in crisis from a short in any circuit where the ecu is providing either power or even a ground.
Some will simply not light or display "no bus" in the information display.
In the case of power being shorted, it is usually a short on the 5v reference circuit (some have both 5v and 8v ref. circuits but probably not that year car mentioned) to ground whether through sensor or harness or.....through the harness itself.
I've seen the dashes flicker from...
1. An idle air control device shorting unresisted 12v back to a driver that is attempting to supply ground to actuate the device.
2. The ASD relay doing the same thing.
3. The O2 sensor heater circuit, an injector, or a coil shorting +12 v back up a line to a driver intended to provide a ground to said devices.
4. Either the map sensor or the thorttle position sensor sending the reference voltage they usually share either to engine ground, sensor ground, or the sensor return line being grounded.
5. The crank angle sensor and sometimes the distributor and, in some cases, the vehicle speed sensor which often share the same reference voltage being shorted to engine ground, sensor ground, or sensor return line being grounded.
What I mentioned above is only one possibility of many that experience has shown can cuse the symptoms mentioned.
Of course, anything shorted on the +12v that the asd relay supplies can also cause this issue.