My money is on the turn signal switch being kaput. The tell-tale on that is the license plate light coming on with the headlight OFF, and brake lights ON.Plus, the left signal NEVER works, and the indicator is on solid turning to the left.
A ground problem will certainly drive ya nuts getting the turn sigs/brake lights working, but it shouldn't cause the license plate light to come on, unless you have a circuit back-feeding thru the t-signal switch.
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Joel Adams
C3VR Lifetime Member #56
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