NEED HELP WITH WIREING!!!!

Does anyone know what the big black wire with yellow stripe on it is for and where the fuse to it might be... I thought i was my ignition but the truck still starts but its where my compressors and windows are wired into and now they are not working and i cant figure out where the fuse is at for that wire... it looks like the wire goes in the dash so i assume it goes under the hood but all i can find under the hood is the big box looking amps and there are 2 30amp and 1 80amp and the 30s are good unless they are both blown and i couldnt seem to get the 80 out and didnt want to break it.. i was getting mad so i stopped for the night. but if anyone knows what im talking about please help me out

in order to get that big 80a fuse out you need to remove the 2 mm nuts that hold that smaller fuse block down. Once that is off there is a little cap that you can open, it's like a plastic door. Once you open those you'll find 2 more 10mm bolts holding that fuse down. From the sound of it, that B/Y wire is the main input from the alternator. You definitely don't want to be tapped directly into this. Run yourself another fuse or two and hook them up with relays. Here's a thread that I wrote on MT about adding fuses:

The EmJay Way

Ok, this was a project that I took on for my truck to make my wire harness cleaner, to have independent fuses for present and future devices, and to use up some unused spaces in my truck. Everyone knows that there are 4 empty slots in the fuse box under the dash, and an additional one that is for the 'head cleaner' (not an option in the US.)

Step 1 would be to find a donor car or truck in the JY. I stuck with Mazda (robbed from a B series and a MX-3) just so I would know that it would fit properly. Others may fit, and these might be available new at a better stocked parts store (Autozone and Advance are no-goes.) Here's a part of my harvest. Some of the circuits in the fuse box will be fed by one power wire. In the B series, there are 2 positions that have 3 circuits supplied from one wire. Here's whatcha get:




I find that the thicker the wire in these, the easier it is to get out and clean up. Well what I did was to take my wire cutters and divide these into the 3 separate components.



Next, strip a bit of wire, crimp down the ears to lock the wire to the piece, and solder it in. The solder helps to ensure that the wire stays in place, could be bypassed but who would really wanna do something that stupid? Sometimes I'll use heat shrink afterward but today I skipped that step. This one truly isn't necessary but helps to make it look clean. There's a shot with some that you can see this.



Now we just slide this piece into the fuse box. It'll slide right in, and you'll hear a 'click' when it's in all the way.



Now one just routes the wire along the master loom to make it look nice and clean (or just let it hang like a ricer.) AFter that this is what your box will look like. sorry for fuzzy pic, still trying to get used to new camera (old camera has better focus on it but new one is higher resolution)



And with fuses in place:



For me, my new circuits are:
7.5a above tail lights: Power seat motor (hooked to 12+)
15a next to PTC: Stereo main 12+
next two 15a next to stereo main: Switched device #1 and #2. [These will power relays, the switches came from a Jeep Cherokee (switch knowledge from R90Baron)]
15a in head cleaner: Remember those mini-wipers I pulled from that Benz a while back? <img src="{SMILIES_PATH}/icon_biggrin.gif" alt=":D" title="Very Happy" /><!-- s:D --> <img src="{SMILIES_PATH}/icon_biggrin.gif" alt=":D" title="Very Happy" />

All 3 of the independent 15a circuits are getting supplied from the main box that are under the hood. I used one of those slots and put a 40a fuse there. The other slot there is for the glow plug system. PTC is going to be replaced with radiator cooling fan, will be supplied with 12+ and run to the sensor in the intake.

and the good pics I later took:
full of fuses


from the back side

Ok looking at a wiring diagram it would appear that the 80a fuse that is under the hood is connected to a black wire. The black/yellow wire appears to be connected to the ignition switch. It starts out as a Black/white wire that runs to a 10a fuse, then it becomes a black/yellow wire after the fuse. This also directs power to the warning buzzer unit and to the switched power for the clock (pin 13 on the dash wiring harness.)

EDIT: also looking at the pictures above I noticed that there is a black/yellow wire going to the back of the fuse box. This wire connects to the 10a fuse labeled &quot;meter&quot;

Wow very nice write up emjay!

Thank you. Kinda off topic, but I have other writeups for mods that I have done as well. As I see the questions I'll start copying my answers here. Might as well be active here to get more input/motivation/ideas and the occasional criticism