mechanical switching Dan - when no direction selected, the brake power goes straight thru the switch to the rear, when a direction is selected the brake power for that side is routed thru the flasher so that it's interrupted .... of course that means you'll have to wire your lights as the newer ones are done,
this 5-9 diagram may help .... study
Cletis' tip a bit and it should come clear - there's no connection between the brake and park circuits except when both lights on one side are blinking
Bill
