What does btn fuse stand for.

Pulled btn fuse current draw gone / pull fuel injection fuse in same fuse panel current draw gone. What now

Nothing has been modified / but I did disconnect alternator / starter. Short is still there strong as ever. Also noticed the gounds are hot on motor as well as everything grounded is hot.

I dont know customer is very unsure of time frame. He had multiple problems when we recieved vehile most all have been corrected already. When we disconnect negative cable with continuity light we have a very bright light /draw / from cable to battery. Until we pull fuel injection fuse from outside fuse box in engine compartment it dims alittle and pulsates. Then we pull btn fuse in same box the lite is out. Sometimes we pull fuse inside car marked fi before we pull btn fuse it goes out. We have just about unplugged everything and draw is still there. When icheck ground on motor from negative cable everywhere I touch is lit / block / valve cover ect ect same issue almost like polarity has been reversed.