I'm new here, and to Land Rovers. My experience with older vehicles tells me that at this point in their lives, someone has dealt with just about any problem you come across.

Vehicle in question is a 1999 Disco 1 SD 4.0/auto. Stock headlight housings with LED bulbs on all stock wiring.

Tonight I lost all headlights, and found a blown 30A fusible link in the underhood fuse box. I have a new one on the way, but in the mean time I'm trying to find the cause. I jumped the blown link with a piece of fine wire, and confirmed that the lights still worked. Almost immediately I noticed that the wire was getting warm, so I set out to find the short. I was able to isolate the issue to the right hand side headlight. With the LED bulb in the fine wire gets warm, if I replace it with a standard bulb the wire immediately becomes extremely hot.

I inspected the harness and found no obvious bare wires, or breaks. With a multimeter I'm picking up some (.09vdc) on the ground pin, and noticing a drop of ~1.5 volts from battery voltage (and also LH light voltage) to the supply voltage wire in the RH headlight connector. I again inspected the harness and I'm still not finding anything. I've read that sometimes the connectors can short out, but I don't understand how that can happen.

Also for the life of me I cannot find a link that works for the rave manual, or any wiring diagrams that don't require a membership to some sketchy website.

Thanks in advance for any advice!

 

link to a google drive is in my signature. You'll find all the manuals there. Go nuts
the headlamp pigtails are notorious for shorting on these trucks but I'm not familiar enough with the needs of LED's to answer your question effectively.

 

I actually found your sig shortly after I made this post. Thank you for those! I'll chop the pigtail off when I'm off night shift and see what happens.

 

I got a minute today and cut the old plug off the headlight and was still getting continuity from power to ground and a voltage drop like there is a short to ground somewhere. I cleaned and inspected the harness all the way up to the firewall and didn't see anything, so I put a new PAL fuse in and soldered in a new headlight plug. Now the lights work, and the fuse isn't blowing, but I'm skeptical.

I bought an extra fuse to keep in the glovebox, maybe it was just a one time thing.

 

Not uncommon for the connectors to get corroded and cause an excessive amperage draw.

 

That makes sense and is something I hadn't considered. I'm still skeptical because of the voltage drop reading right off the wiring with the plug cut off. If it gives me any more trouble I'll do some digging around at the relay and upstream of it.