Electrical problem on 1994 Isuz box van truck

You are aware that this forum is not primarily working with mind readers, and psychics. Because I do not have my chrystal ball charged up, I feel that it would be better if you could answer a few questions.

• What is the inline fuse powering?
• What is the inline fuse powered by?
• What changed since the truck worked correctly?
• Is the engine gasoline, or diesel?

At this point, this guess is going way out on a limb, but how about this.

The accessory that is powered by the in line fuse, is fed from the wire that powers the fuel solenoid on the diesel injector pump. When the engine is turned off, that wire is grounded. There is a capacitor, or battery in the accessory, that trips the fuse when the ignition switch is turned off.

Looks like I have to make a few assumptions here. I think you are talking about the 25 amp fuse in the line supplying the ignition switch. If that is so, either someone has made some wiring changes that shouldn't have been made, or rewired the ignition switch incorrectly, or the ignition switch is bad and needs to be replaced. Sounds like the ignition switch is shorting the supply to ground in the off position. That's where to look. Good luck.

I feel the battery charging system ( alternator ) is defective . This might be leading to fuse blow at switch off. Inform me your finding at narwal_sunil@yahoo.com

Disconnect alternator or have it tested , may have bad diode .