1990 80 Series Landcruiser headlight problem

Hi, my son recently bought a 80 series Cruiser and the headlights don't work. When you put the headlight switch on, the parkers work but not the headlights(low or high beam). We have changed the headlight relay in the engine bay fuse box and while we were at it we replaced all fuses in that fuse box and also in the dash fuse box as well.

We put another headlight/indicator combination switch in as well (2nd hand , not new) but still no luck. There is power to the two 15 amp fuses when the headlight switch is on. I have put a multimeter on the red/white wire from the combination switch connection under the steering collumn and to the harness connection near the washer bottle which goes to the headlight relay and the multimeter doesn't move which I assume means there is a break in that wire or the wire goes to something else under the dash which is causing it not to work.

I run another wire from one end of that wire to the other end, basically bypassing that wire and I can get the headlight to come on but when I put the high beam on the high beams don't work and the low beam goes out. I'm at a loss as to what else to try, is there something else under the dash that the headlight wire may go to first? Any help will be appreciated, I hope I've explained everything properly we have done so far to help with any suggestions.