Need pictures...
You don't need resistance on both the power and ground sides of LEDs - one or the other is all that's necessary (power side is definitely better). Most pre-assembled LED lighting already has the necessary resistors built-in so unless you're building your own from loose LEDs, you may not need resistors at all.
On the other hand, if you're adding resistors as load equalizers to make the turn signals work properly with LEDs, it's much easier to replace the thermal flasher with an electronic one.






