well just reran wires from battery to a relay to power backup lights, pulled power from taillight to trigger relay all is fine...except the backup sensors do not work, the info box on dash says check backup sensors, now what? which way do I look for problem or is this the way they will stay? help!!

 

Trace back all the steps you took before they stopped working. If they worked before the work was performed than you most likely did something wrong.
That, or you tied into the sensors circuit and the relay is pulling to much current and in turn giving you a failure.
Are you pulling off 12v at the reverse light power wire?

 

If you pulled the power from the trailer harness is could be detecting a trailer hooked up and bypassing the sensors.

 

yes pulling 12v from backup light, just to run relay. 1 wire from battery is ground and the other is main power, both to relay. then a trigger wire from taillight backup bulb, last power from relay/ battery to the aux led backup lights. it was originally tied into trailer harness, that's when backup sensor acted up, I rewired the whole setup from battery back, to stop the sensor problem but no go! if I had to re-solder a wire that broke in trailer harness while redoing this would that cause a resistance that canceled the sensors? I had to add a small piece of wire to the broken wire because of how it came apart, soldered both ends.

 

The BCM may have a fault stored in it and may need to be reset at the dealer. That is if the rear sensors are even tied into the BCM. I'm not sure.
If it is anything like the turn signals their will be a current range that will trigger a fault. So if it sees anything out of that range, say 0mA it would know the bulb is blown and give you the hyperflash. Which usually doesn't throw a fault. But if it reads 5A when it should only be 4A it would think it is a short and cut off that circuit until it has been reset with a scanner.
I don't think your repaired wire is the culprit, just so long as it was repaired correctly.

 

just got and installed new tow wire harness and still nothing. is there a way to reset the backup system? like disconnect battery? now with the new harness I know that part is all good, what and where do I look next?