Here is a real wierd one on a isuzu elf wof

failed on foog light not working my mate said i just fit other fog lights to wof lol
no cant do on the elf the inner lights of the headlight is the foog yellow light .
Right so i went to test things all good fuses and all cant find wiring diagramm with google in a hurry so i know it must be real basic tested power at switch ok so i remove a bulb as its not unusual to have 2 bulbs out bulb is fine.
So i hook up multimeter i have 11.5 volts at holder.
So i pull out the loadpro test leads and do a voltage drop test at the conector bulb holder voltage is out move my lead to chassy ground 11.3 volts on bulb holder . tell guy to get charger on his battery to make sure we dont drain it while i hunt for the bad ground as the hot side would light a bulb.
i splice a new greound in to his harness as i cant get to any of the wires under ther
nothing still so i remove the conector for whom has a plug and 6cm wire to the bulb holder,
Turns out the negative wire has a high resistance inside the bub holder no corrosion nothing to be seen in the holder
Said to him you have 2 options now you need a new holder or you drill a hole and solder the wire on to the outside of the housing to give it its ground back because thats how i made the bulb glow for a test by holding my ground on the outsiide of the bulb holder.
Wonder if bigfatmat ever seen stuff like this.?
Hope i did not misspell his user name.
other side did not work either
I told the guy i dont know whats wrong overe there but you fix that and then i go and find out what is wrong over there.
i cant know whats wrong untill i run all tests over there also. bulb is fine there we tested that one so it must be the harness somwhere

crap cant edit the title elf needs a COF also has hubometer on wheel.

lousy earth for the entire light bucket?, the headlights are wired earth, the rest are contact earth, clip one of your jumper leads from an earth back to the light body to check

late thought, the ELF don't have a wired earth do they?, could be as simple as a broken wire further down the loom

I've had problems with wired earth systems and found that the earth wire was broken - in the loom - in the cab hinge area ( on tilt cabs)

Magic. Based on my belief that electricity is magic , which this post supports, it needs magical healing.
Being nearly Xmas have you tried some decorations on this elf?

Is this the lamp that uses 35w h1 or h3 bulbs or a 21w bayonet fitting. Bad earth at holders are not uncommon had one on a mitsi the other day. I just pulled the wire out from bulb holder to brake it off the base poked it back through and soldered it back on where I could get my soldering in. In your situation I would just solder it on somewhere to save time and trying to find another holder

its this 21w bayonet fitting.

no its a normal single filament bulb like you find on any 80s and 90s cars tail light i did not look at the watts on bulb the bulb is jellow coated to shine a jellow light.
the harnes is fine to the connector . i cut the earth wire off in the end just outside the bulb holder to ohm the 20 mm wire in to the socket and its fully open somwhere in the holder no green crud or anything
this is what the harnes sortof looks like different plugs and yellow bulb but the designe is this the fault is in the last 1/2 inch on earth wire in to the body of the connector . told him to drill a hole and solder the wire on to the housing , or buy a new harness bulb holder
http://i.ebayimg.com/00/s/NjE0WDY5OA==/$%28KGrHqN,!o0FBk,-3HOCBQsUWSfjT!~~60_35.JPG

bigfatmat1 where do you or your company you work from source wiring diagramms from. i find it ultra hard to find anything on the internet other then for american sold cars like mitchel1-diy

I do not use wiring diagrams. I don't really need to. I work for a dealership of a few brands so have them at my disposal. I do use a cable tracer though.

Just yank on wire to pull it out of base then poke it back up through hole and solder it onto metal outside of bulb holder may need some acid Flux and a good hot iron wire may need slight extension