Locating this wiring harness

[matt_ew]

Tail light is out and it's not bulb or fuse. I've got continuity from the tail light circuit to Pin 9 on the T17n green plug under the passenger seat. Reading voltage of the feed to the pin from wherever it comes from I get 0.3V compared to the pin for right side tail light at 12V.

So problem is whatever is feeding T17n Pin 9.

Anyone know where the B144 wiring harness is and is it a job to get to? Or is it just under the floor?

Please help

Matt

 

[stan-the-man]

Your BCM is sending signal to the light, nothing else feeding that. This point refers to split point in the loom where it splits to multiple points if needed. Have you tried if you have continuity from piun 9 in 17pin light green plug to BCM?

 

[matt_ew]

Getting to BCM was a job that I wasn't prepared to do on my own but I measured 0.3V at pin 9 which was weird. After disconnecting and reconnecting the battery pin 9 started reading 12V. I didn't think to check if my +ve cable to the tailight had continuity to ground though so did that and found the problem! Each time I'd connected the system up it was just going to ground and causing BCM to stop outputting 12V. Why 0.3V i'm not sure though.

Took apart the taillight again and removed all the bulbs. checked there was no continuity between circuits or ground (there wasn't), so put the tail lights back in and they work! Rest of bulbs went in fine too and all seems to be working. Somehow at some point (even after someone else changed the bulbs) the tail light circuit was touching ground somewhere causing this whole problem.