What I didn't follow was WHEN did the lights flash? Just sitting in the driveway? Only going down the road? The one post said that it will throw an error code up in the computer because the trailer leds aren't enough load for the system, what does it do if there is NO trailer connected? Only thing I can guess is that the computer has a set amount of current that is expected if a trailer is connected. If that amount is zero, it knows there is no trailer. Some current, but not enough, it thinks there are bulbs out. The current sensor would have to be seperate from the main bulb system because any trailer that is added (even leds) would be increasing the current draw on the system. And this is all an educated guess
. Computers are great, but my 67 Cougar never accelerated to 110 MPH on it's own (unless I was mashing on the gas peda).