i tried that but if i bridge them the highs stay on all the time. even with the ignition off. and i have swapped the pins 30 and 87 over like you said. but they work fine with the diode in there

ok. i believe the diode is a one way link to stop voltage running back to the lights,

i can have a look at the wreck in my yard and see what the second one is for...
it might be for abs,ecu or the fuel pump relay...

try run the car with the second one disconnected??

i ran the car with the second one fitted to the headlights. the car started and ran fine but it might be a weaker diode as it melted thru when the highs were on for about 5 mins (was adjusting the lights)
its not the fuel pump or ECU i dont have ABS so its not that. all the lights inside and out ran, the gauges all worked. even the ciggie lighter still worked.. maybe its for the trip computer or something that i dont have. (my trip comp was broken so i removed it and put in a blank) i will head out to my mates tomorrow arvo and see if i can get the diodes outta his cars. if i put the one thats meant to be in there in there it may just fix the drama..
BTW what do do with the leftover grn/orange wire for high beam? i have cut it and taped it for now.

So with a standard eb on high does it only have the highs on and lows off at high.
If so can all 4 be on by replacing said items in this thread.

i would assume so

instead of getting a diode all i did was go to supercheap auto and grab a relay kit for extra spotlights. was like $24.95 and wired it in.
instead of a switch i put the wires coming from the diode holder on one side to the switch (30) and the other side of the diode holder to the power out (87) and it fixed the problem of not having a diode and also allows more current thru the system..