Headlight issues

[Kevin911sc]

Any idea whats causing this?..when I put my turn signals on, my headlights dim...I keep getting flashed because everyone thinks im driving with my high beams on after I signal a turn and they see the intensity difference....actually had a officer blind me with his spot light for it, real professional. Its a 1986 911 with euro lights

[Paulporsche]

Check your grounds and all other electrical connections, the stalk switch, and your headlight relay. Also make sure your high and low beams are functioning correctly to begin with.

Often, after years of use, the stalk switch connections fatigue and multiple functions can occur simultaneously. There are threads on checking and fixing the switch by bending the contacts.

[darrin]

also a good idea to install headlight relays (especially if running european bulbs) as the stock wiring runs all the headlights' current through the turn signal, which can cause heat buildup and potentially accelerate the connectors' fatigue. However, even though I added relays when I had this problem creep up on my'86 a few years back, I just noticed that the connections need to be tweaked again.

[dfhtrhjn]

Ha, I fixed this problem last Tuesday on my car.

I had to bend a lead back into place on the turn signal switch. My high and low beams were both on, so the light would dim when I used my turn signal because the highs would turn off and then back on again. It always looked like I was flashing people...
My high beams worked fine when I used the switch though.

If that's the source of your problem, then checking the switch is pretty quick and easy, about 20 min.
1) Take your steering wheel off
2) Pull the plastic cover plates on the column
3) On the left side you'll see the metal leads (connecting points) that trigger your high/low beams on your turn signal switch. Those leads could be bent, and engage/disengage lights when you're signalling. Just operate the switch and watch the leads move. I had to bend one of mine 1mm and it works correctly again.

[Jdub]

A common enough issue, esp. when upgraded lights (H4s on my SC) are installed and cause a greater current draw. So you put an aftermarket relay in the circuit as per darrin so the current instead runs via wires that can handle the load.

But it it mechanical as well sadly, so do check that out. If $ is no object get a fresh stalk, since they will only cost you more 5 years down the road.

[sugarwood]

I just installed a new $125 stalk from Pelican. 911-613-305-01-M78
Even I was able to install it.
I will post a bunch of photos when I can.