how do you check and fix headlights on an old landrover 110?

I had a very similar problem on my 90. Excessive load (possibly caused by previous owner's extra spot lights) had caused the contacts in the switch to overheat and melt the plastic mount. So the contact in the switch came loose - result was no lights at all when you switch headlights on normally, but get full beam when you use the flash. Short term solution was to short out the contacts inside the switch. Longer term fix was to replace the switch cluster.

eeyore
January 2008

When you say OK on high beam I suspect you are referring to the passing light/flasher switch.
If this is true and there are no rear or side lights either, and the fuses are intact, then it would be fairly safe to bet on a fault light switch cluster.
Before it is replaced though, it is easy enough to check it with a voltmeter and someone who knows how to use it.

Colin
January 2008