Suspect a charging system problem. Most commonly look for a defective internal diode inside the alternator. To find that have the system professionally load-tested. When one of the six diodes is defective you will only be able to get exactly one third of the alternator's rated output of around 90 or more amps, and "ripple" will be very high. That ripple can irritate computers, of which the instrument cluster is one, and cause them to do strange things.
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Friday, September 28th, 2012 AT 5:33 PM