turn signal weirdness

[kcobean]

I have LED front turn signals with standard bulb rear signals. With the light switch in Stop Light position my turn signals behave normally. With the switch in the Service Drive position (headlights on) the left front turn signal does not flash. The left rear does, and both right turn signals behave normally. I changed out the turn signal switch to the new style, self cancelling one yesterday and immediately after, the left front turn signal worked but the right one was intermittent or didn't work at all. Now it's back to the behavior of the left TS not working in Service Drive. So something seems inconsistent. Do I need the flasher module because I have the LEDs in the front, or has anyone seen this before?

 

[dilvoy]

Check all of the grounds.

 

[Jericho]

Ditto on the grounds ,My worst enemy!