Porsche Enthusiasts Club Forum

Hi, is the main beam supposed to turn off when you turn the high beam on?

common sense would tell me yes that's correct, because of the electrical load of having 55W and 65W on at the same time would put a massive load on the wiring and relays

I know my 68 does that, high beam turns the low beam off.

The main (high) beams may stay on with the dipped beams if you are flashing somebody. However, with the stalk thrown all of the way towards the dashboard the dipped beams will turn themselves off due to the reasons stated above.

This sounds like an oval dash. The square dash stalks only pull towards you, not push. So for full beam, you pull the stalk and release it, then pull again to switch off full beam. Flashing is an acquired art of not pulling the stalk so far that it clicks on permanently. The light bulbs however, operate just as you describe.

thanks guys, it's just that modern cars seem to leave them both on. Having said that I have a separate harness for the dipped beam and draws power directly from the battery and the switch is only used as an "actuator". Now I just need to adjust the light aim.

Modern cars with single filament bulbs will leave both sets of lights on (e.g: a car having H7 bulbs). It is bad practice for a dual filament bulb to do this due to the reasons mentioned regarding heat thresholds of the bulb.