Headlights

[1975porsche]

Driving last night and low beam lights on my 1975 911s look like they are half the briteness they use to be any ideas Thanks Glenn

[HunterVonWurst]

Check your grounds.

[fintstone]

Cec your alternator or battery

[80-911SC]

+1 on the grounds, also all connection at the socket, your bulbs and the fuses. degradation/corrosion in any of these could lead to dimmer lighting

[Quicksilver]

Originally Posted by HunterVonWurst

Check your grounds.

There is only one ground for each light so it is the same one for the high beams. If the high beams are ok them we will need to look elsewhere.

A common failure point on higher mileage cars is the dimmer switch/turn indicator switch. The expense of this switch is a reason that people commonly upgrade the headlight wiring with a relay.

Porsche is odd in that they put the fuses between the switch and the headlights. To bypass the switch for testing you can remove the headlight fuses and apply 12 volt positive power to the downstream end of the fuse connectors. If the light is full bright then you know the problem is upstream.

Because the switch is so expensive if it has become marginal I would fix it by cleaning the contacts and adding a relay to reduce the future load on the switch.

[HunterVonWurst]

Originally Posted by Quicksilver

There is only one ground for each light so it is the same one for the high beams. If the high beams are ok them we will need to look elsewhere.

He didn't mention the high-beams.

Step 1. Check your grounds (including ground cable from battery and chassis/engine straps).

Step 2. Check everything else mentioned.

[1975porsche]

thanks for information .High beams work great .