How do you do the wiring for the rear lights on a 1973 vw beetle?

there are 4 wires coming from the car and only 3 on the back of the light.How do you do the wiring for the rear lights on a 1973 vw beetle?best bet is to turn it on do the lights and use a multimeter/tester...youll soon sort out which is which.How do you do the wiring for the rear lights on a 1973 vw beetle?Do you have the right lights. Might one be an earth wire that should connect to bare metal. I dont know, should have kept my mouth shut. Haynes manuals are good for beetle repairs.How do you do the wiring for the rear lights on a 1973 vw beetle?if you have a Haynes auto manual it might help, because they do keep wiring diagrams in there if you do not have success, contact me @ shanewater14@yahoo.comHow do you do the wiring for the rear lights on a 1973 vw beetle?
Don't waste your time with a Haynes Manual, they know nothing about electrics.