Trailer wiring problem

[Tom62]

Hello, I have a 1997 4Runner SR5 with the towing package. I recently bought a small boat and brand new trailer. My problem is that BOTH blinkers blink regardless if you blink left or right ? All other lights work fine.
At first I thought it might be the ground on the trailer, I checked that and it's good .... Then I hooked up a VM to the connector on the truck, and with the left or right blinker on I get voltage (on/off/on/off) on both left (yellow) and right (green) wires?? Am I missing something?

Any help would be appreciated ...Thanx Tom

[RobXS]

Do you have an OE wiring harness or an aftermarket? I have had issues with the Hoppy aftermarket harnesses going bad. I would check the wiring. It sounds like a short somewhere.

[Tom62]

Rob ... I traced the problem back to the 5 to 4 wire adapter ..it was the original Toyota harness/adapter. It was bad .. replaced with after-market harness from NAPA ..... Thanx