Helping a friend chase down a parasitic drain on his wifes 2014 Buick Enclave. .5A drain after all lights and doors are closed. Takes a few minutes to settle out, but .5A drain constant.

There is two inline fuses, both 15A, taped to the positive (red) cable at the battery. Also what looks to be a choke made onto the + cable that is wired to these inline fuses.

The wiring from there goes through a raceway under the passenger side floor.

I unplug both inline fuses, the drain goes to .1A, but car will not start. But if I unplug the one closest to the end of the cable, car will start and the drain goes to .1A after given time to settle out, a few minutes.

The following picture is of the top of the battery showing the the two inline fuses.

Can anyone help me out with this? What are the two inline fuse holders for? What is the connection with starting the car? With both fuses installed, why .5A drain?

She is second owner, nothing aftermarket installed.

What is the spec?

Is the battery not starting the next day?

Not sure what your first question is about? Sorry.

I should have mentioned the time to no start, which is three days and battery to dead to start engine.

How old is the battery?

Battery is two months old, also passes a load test.

Also the alternator is working fine.

What are the fuses powering?

1 15a fuse is to the ECM,and the other is to the Telecommunications Interface Control Module.

That'* factory?

Yes we found mention of that in the owners manual about towing?? It does appear to be factory?? Looks like an after thought to me.
With the TICM fuse pulled it drops the amp draw from .5A to .1A. Wonder if there is a problem with onstar module or??