[Stl-986]

I have seen the same thing on several of these cars. It's a heat & age plus too thin of a wire/insulation.

My opinion is that they used too thin of a wire with too thin of insulation. Add heat & cold cycles to that and the wires were going to crack eventually, just a matter of time. I am more surprised when I open one up to replace either bulb to NOT find any wires cracked then I am to see them cracked.

When you add the internal wiring with the wrong sized wires to the rest of the headlight wiring and then put 20 years on the car and it's going to be an issue. On 944's what we used to do is just run each headlight off a relay & a new 12v wire to the fuse panel or battery and instantly saw a change. Basically used the original wiring for turning the relay on/off. Porsche isn't the only mfg to encounter this, virtually every mfg has or will have this issue. Also see this a lot on Jeeps.

Now that the new headlight standards have been approved I think this may become a non issue on new cars & LED's but we are stuck with what we have. Best thing to do is clean your grounds and fix any wiring issues you encounter.