k0ua
Epic Contributor
Eric, I would for sure try the noted above "fair-rite" ferrites first, and be sure to make at least one loop through the ferrite if possible. If that does not do the trick. i would take them apart, and solder a .1UF 100 volts rated or higher disk ceramic capacitor across the 12 volt leads as close as possible to the lights, inside the housing. You can also try bypassing each lead to ground with a .1 also. You could also try a .01micro farad especially if the interference is in the vhf spectrum.