Dysfunctional headlights
 

Vehicle = 1980 911SC [Euro]

Made the conversion from old-style headlights to the H4 system this wekend and >> what do I have?

I have the drivers side nice > bright and full of lumens.

The pax side however is pretty dim...

This cndition may have existe with hte old headlights as well, so may/may not be a issue of the H4 conversion.

But why would one side be "normal" and the other so dim??

Help please!!

Was there no problem before? The headlight/turn signal stalk is a very common weak spot. Some folks have had success cleaning the contacts in the switch, but it's the same amount of labor to just replace it. So decide if you want to do the job once and spend $80 on the new part or try to save money and maybe end up doing it twice and still spending $80. You should also install the Marcus Sucro relays before using your high beams. This will prolong the life of the new switch.

Installing the relays may solve the problem in itself provided the rest can provide enough juice to hold the relay in. (Not much needed) I'd also clean the contacts frst as Rick suggested.

When you switch to high beams, do the sides alternate? In other words does the side that was bright get more dim and the side that was dim get brighter? Because "Porsche" put each hi/lo filament on it's own fuse, if one of the wires to the bulbs is crossed this could be the source of the problem. Mine was like that. Changed the wire in the fuse holder when doing the relays and that solved the problem.

Clayton:

when I switch to high beams the same "dysfunction" remains.. the drivers side is bright and the pax side is "weak"...

If the bulb is dim, your either loosing voltage somewhere or the bulb is bad. The first thing to do is confirm the bulb is good - if you switch the drivers bulb to the pass side, are the symptoms the same?

If the bulb is good (and my guess it is), then from that description, the first thing I'd check would be for a bad ground.

Pull the headlight and check the voltages with a multimeter. What are you getting at the light (High Beam to Ground, Low Beam to Ground)? Can you measure a voltage drop from the ground of the headlight to the ground of the battery terminal? How about a droop from the low or high beam side to the +12 on the battery. These numbers will tell you exactly where you're loosing voltage.

Porsches, esp old ones, are known for thier wiring gremlins. Ground points oxidize and build up resistance, connections breaks after 20+ years of being jostled. A multimeter and some probing can tell you quite a bit.

If both high and low are in volved check the part that hey share, the GROUND.

It is also a good idea to go to relays if the car does not now have them.