[Xack]

I had a similar thing with 2 incandescent bulbs in my dash linked to the individual circuits for showing turn signals. Also when I turned on the lights you could actually trace the lights coming on in a wave across the panel. The opposite side bulb would light dimly as the main bulb was bright. This was true for both bulbs. I had a daisy chain power to the dash gauges and bulbs and a similar approach to the grounds on each device. All I did was run each device ground wire to a common ground under the dash. That cured the problem. The lights on the dash are noticeably brighter.