9 Pin Data Link issue

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(01-08-2021 )Grizzly Wrote:  2010 Peterbilt 387
ISX
Data link is stopped communicating with mcp50 by Omnitrac. Thought it took a crap from being old, but installed a new IVG and it’s not getting power either.
What I’ve checked and know so far:
All fuses behind glove box checked with ohm meter and test light. All good.
Checking pins on data link plug:
Pin B (power +) light the tester
Pin C (CAN J1939 HI (+) When I touch it, no light, but kicks my high idle off.
Pin D (CAN 1939 LO (-) gets nothing. And I can’t remember for sure if it was this pin or not but ohm meter didn’t zero out.
Keep in mind I have minimal to zero electric know how talk to me like I’m 3 lol.
Thanks

Light tester or voltmeter will not work to check J1939. Turn ignition off set the DMM to ohm meter 200 ohm range. Between J1939 HI and J1939 Low should be around 60 +- 6 ohms.