I used simple 80 or 100ohm resistors, one on each of the front signal lights. They can get hot in use, like if you leave it blinking for 15 minutes, so secure each one with a metal tab so they don't melt any nearby plastic. Resistors are much easier to install than LED flashers, cheaper, and much more reliable. You only need two, not four, each connected as shown, one one each front turn signal.