Ok thanks. I wonder what's the fuse block bus bar?
It will be the supply that the fuse box draws from - its inlet manifold!
When you pull the BATT fuse one of the fuse boxes should lose all power.
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Ok thanks. I wonder what's the fuse block bus bar?
It will be the supply that the fuse box draws from - its inlet manifold!
When you pull the BATT fuse one of the fuse boxes should lose all power.
With the BATT fuse in, remove any fuse from the underhood fuse array and find live voltage on a connector. Pull the BATT fuse and if the voltage you found is no longer there then the BATT fuse serves the underhood fuse array. If it is still live than do the same with the the fuse array inside the driver's door jamb. Whichever one dies is served by the BATT fuse.
I suspect it is a component downstream from the ENG fuse that is the problem. There's a few of them. EVAP cannister, O2 sensors, EGR valve etc.
Apologies - I've confused ENG with IGN-A fuses.
GM handbook says IGN-A fuse is for ignition switch - as useful as a chocolate tampon.
In Haynes I can find 'IGN E mini fuse 10A' going to (via pink wire) 'fuel pump balance module',
and, 'IGN mini fuse 10A' going to (via pink wire) to 'AC compressor clutch relay'.
That's as much as I can find.
Your alarm isn't helping at all. Can it be got rid of? Alarms are well known to create problems (drained batteries being one of them). Bin it if you can.
Maybe there's more wiring/fuse info in the GM manuals - do you have them?
If it was known exactly what IGN-A fuse serves it could be left in and components downstream disconnected in pursuit of the drain.
That alarm has almost got to be aftermarket and the dealer just installed it. I've never seen a GMT400 with any kind of factory alarm.