[schurick]

maybe you have a bad ground? I'd run just a temporary spare wire to the ground and check it that way

hopefully taillights aren't like headlights that the TIPM can turn off when it gets moody

 

[schurick]

you can try linking them. Our cars are sensitive to extra load and resistance on the electrical circuit so be careful

 

[schurick]

besides Haynes there are places like alldata diy and mitchell1, both of which cost money but should have wiring schematics.

my guess is before the end of the day intrepid will reach in that magicians hat and somehow pull out a schematic for you.

as far as fast blink goes, it used to indicate one of the bulbs being out. With a mix if LED and incandescent, nit sure what it would be. Maybe you have a bad socket ir connection somewhere and it is drawing too much power.

LEDs are finicky little bastards and get upset easily if something isn't quite right

 

[schurick]

check your brake switch

if you have access to an above basic code reader, try that. It may have a code that doesn't trigger a CEL. I know on my truck I had a code for brake light switch.