Quote:
I will try and explain in words. You will need a relay for sure and you will need one momentary contact switch to operate the relay as normal, say to turn on the high beam. you also want this relay to latch on, so take a link from the output to the lamp and connect it to the relay coil, so that when the relay is operated by the momentary switch it latches on, now if this link wire is connecteed through another momentary switch that is normaly closed the relay will stay on untill this switch is pressed. so you would have two press switches, press one you get high beam press the other you go back to low beam.
Might be easier to replace the switch in your custom holder with a latching switch if you can get one to fit in, maplins might be able to help, that way you only need one switch, but you would still need a relay
Hows that. 
Nicely put 
I couldn't figure out how to word it 
Cheers
Steve
CHAOS, MAYHEM, DISORDER ................................ my work here is done
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