Reverse light flashing when turn signal on

Can't seam to figure this one out, just had to switch to aftermarket headlights (used original bulbs no wires cut) and now when I use my passenger side turn signal the reverse dash light (transmission) light flashes? All bulbs seam to be working fine but would love to get a few ideas what's going on?

 

5 hour bump... anyone have any ideas?

 

Possible the lights a grounding each other out. Similar thing happened to me after wheeling for the day. Broke my 7 pin and it one of the connectors enough to where it was touching another one. So when I pressed my brakes my reverse lights came of and I noticed it by on the dash saying I was in reverse while braking. So maybe you just grounded out some wires.

 

Thanks! I did notice this evening I had grounded out my fog lights so going to replace the relay tomorrow and see if that helps.

 

Np. Don't know if the fog lights would cause that but hey don't hurt to check

 

As expected the relay replacement didn't make a differance (well they work now) so the trouble shooting continues. Blinkers rapidly flash with headlights on but all bulbs appear to be functioning.

 

Dead thread revival hope, did you ever figure this out? Mine randomly started doing the same this morning. Left turn signal selected, transmission reverse indicator flashing. Tripped me out. https://imgur.com/a/uitrhoG

 

My 04 4Runner started doing this as well, left blinker, Reverse light flashes fast and if I do it while I’m driving over 30mph it’s as if downshifted and goes back to normal when I turn the left blinker off.

 

Any answer on this? My 4Runner is doing the same thing.

 

Usually it's in the trailer wiring. Check your trailer connector for corrosion and wiring for damage.