I have a 1999 Dodge 2500. I recently installed my emergency warning lights on it, included was the wig-wag for the headlights. But as I found out the hard way, you have to use Factory specific flasher for this application, after the fact..... Anyways, in order to install you have to tie into the Highbeam for each light, I did so with a simple splice as diagrams show. But for some reason there is a problem doing this to 99 and newer models. I removed the wig-wag system completely after finding out that it doesnt work, and restored the wiring to factory settings. Now I have the left headlight dim and the right headlight fine even though both were spliced. I'm 99% positive its a ground issue, but I cant seem to find it. Ive retraced the wiring back to the lamp switch, and checked all grounds, but no luck. Dealership insists Im missing something which is very likely, but I just wanted to see if anyone has an answer and/or suggestion before I take it to them. I would also like any info on the reason why the 99 and newer models are affected this way if anyone knows. Thanks!