OBD Fuse Parasitic Draw - 2013 Tacoma

Had some problems with my battery- got my truck in 2013 and live in the south where OEM batteries supposedly have a life of 2 to 4 years.. This all started after I did my retrofits and did some extra wiring but I'm not sure if it is directly related.

Regardless- I've narrowed down a parasitic draw to my OBD 7.5amp fuse. With the fuse plugged in I get a draw of 300ma. With it unplugged I get a draw of 40ma.

My question is WHY? I do have an Ultra Gauge but with it unplugged I get the same draw.

What runs off the OBD fuse besides the OBD itself?

 

My guess would be something in your new wiring.

Change management always asked 'what changed' when something goes wacko, and that becomes your point of beginning.

 

But how would my headlight wiring be connected to the OBD fuse? -- could it be coincidence about my old battery giving out and the new wiring?

 

Can you draw out a wiring diagram?