I have a 1997 EF-NS Hijet S110p (non dump). I'm working on adding a backup warning speaker [This guy]. While looking into where I can land power I ran into something I don't understand in the fusebox. the IG1 and IG2 fuses are both missing and yet everything electrical on this truck works fine. I couldn't find anything in the electrical diagrams that are supposed to be fused after IG1 or 2 and every video or picture I've seen of one of these fuse boxes has those two fuses missing. I also probed both fuse points in the box while the truck is running and neither side of either fuse has any voltage with the truck running. I would have expected atleast to see power on the battery side of the fuse contact. My question is, does anyone have any diagrams or reference material that explains what these two fuses are typically used for? A secondary question is does anyone have any recommendations for which circuit to tap off of for power of external devices?
I added a usb charger for the dash. I wanted it to be independent of the ignition key. I probed the wires in the plug shown in your last photo. I found one that was always on. It turned out to be the horn circuit. I unpinned that terminal from the plug, cut off the freed terminal, and crimped the horn wire and my new wire, both, to a new pin that I put back in the plug. I was forced by a state vehicle inspector to add a 3rd brake light up high. For that I ended by connecting directly to the brake light wire at the rear of the truck then running wire all the way back to the rack behind the cab. Since the light is LED, I think the small current it uses is not a problem.
So it turns out, the information I was looking for just doesn't exist on the internet. So I bit the bullet, pulled the fuse box out, and mapped each connector and fuse trace. First, I created a diagram that outlines each connector on the fuse box to the pin number as described in the electrical diagram manual. I did my best to color code the wires as they exist on my truck and as they're called out in the manual. (Note: Connector pinout numbers in the manual are referenced as you're looking into the connector. Numbers here reflect the manual connector numbers as you look into the fuse box. Ex. JI1 in the manual is the top left of the connector. When you plug that connector into the fuse box it will be in the position shown in this diagram). If you look closely at the connector and fuse housings in the fuse box there are very small numbers on each pin/ fuse leg. These numbers indicate what terminal points are connected together internally on the fuse box. I mapped all of the connector and fuse points using these numbers on the fuse box. The reason the IG1 and IG2 fuses don't have power is because there is nothing landed on the JA1 pin which is where the incomming power for that circuit would be terminated. Finally I used the information from these two diagrams to re-pin the JI connector to land power through an external switch to the speaker power using the HAZ (Hazard/Horn) fuse. Here's a diagram of how I wired the speaker. I'll probably switch the power to the ACC fuse because I didn't realize the HAZ has power even when the truck is turned off and I don't want it to vampirically drain the battery. Here's a picture of how I have things wired up now. (Ignore the messy wiring, I'm going to clean this up now that I've tested everything works)
This is awesome! Thanks for publishing this! What software do you use for drawing the elec. diagrams? Very slick
Thanks! Figured if it was something I was looking for someone else out there might need it too. The software I use is called draw.io
