2006 Cm 870 cold weather derate

[tree98]

You should be checking for 60 ohms out on the data link connector. On 870's they are hiding behind the air compressor usually. Battery power on the J1939 plug is pin B.

If your getting power and ground through the plug up to the inline device, and it isn't powering up, it's possible you got a dud. It does happen time to time.