Backup light wiring question

Im installing OPT7 tailgate light bar, i used the 7 pin to 4 pin adapter and all works
except backup lights, i have tried T-tap at adpater and now i have ran the white wire to the
taillight. At the tail light i have a white wire with black stripe and a red wire which should i t tap off of?
thanks

 

Get a 7 to 5 way adapter instead.

 

I did but I still have to connect the white wire which is for the backup lights, I tried T-tap to center wire at 7 to 4 pin adapter, I guess my problem is using T-tap in stead of making a better connection, gonna call it a night and try tomorrow thanks for the info.

 

t-taps suck. get some heat shrink crimps.

 

Well you were right, T-taps caused me much grief. i soldered it and all is well.
thanks