Have 2001. 5 4wd Cummins,i live in Canada so we have the Daytime running lites on our vehicles which is a good idea but the question i am asking is this-the Bright Box doesnt work very good on vehicles with DRLs. JC Whitney also has a unit that makes the dims and brights come on at the same time but again this unit dosent work very good with DRLs. One can shut the DRLs off by just pressing the parking brake one notch , so am thinking that if one shut off the DRLs with the brake then wired the relay in on the ground wire,(the ground in these trucks are switched)that goes to the brights and connect the relays wires to the dim ground wire so when the ground was activated to turn the headlites on it in turn would activate the relay to make the dims come on also and there would be no feedback thru the wire that runs the DRLs becouse its turned off at the brake switch,i dont have a wireing diagram so i dont know if this would work,maybe someone has tried this.