Weird electrical problem-headlights - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Lil bastard · 09-10-2008, 01:34 PM

I'm still leaning toward the starter (ignition) switch. Not all possible symptoms are always present when one of these fails. Of course, the headlamp switch must also be somewhere on the list of possibilities, but this is pretty easily ruled out using a DMM and checking for continuity at all the various positions. There are no relays for the headlamps, just the foglamps, so not a possibility.

If it were me, I'd start by checking the headlamp switch with a DMM and if that passes, concentrate on the starter switch.

jhandy · 09-10-2008, 06:52 PM

Thanks for the advise, here is the progress....
Fuses ok.
Bulbs look ok, I have no direct way to test them. (filliment looks intact)
Engine on, low beams dont work (both of them), city lights work, high beams only work when pulling stalk, fog lights work.

This just happened, I did not mess with anything, one sec it worked, and the next it did not. (can both bulbs blow at once?)
I will check the switch (stalk) and the light switch (knob) tomorrow.

I am about to give up here soon and just drop it off at the dealer. Nuts and bolts are easy for me, electrical problems have always eluded me for some reason.

I will keep y'all posted.

PS...What is a DMM and where do I get one?

Lil bastard · 09-10-2008, 08:17 PM

Quote:

Originally Posted by jhandy

Thanks for the advise...What is a DMM and where do I get one?

A DMM is a digital multi-meter. These can be had for as little as $10 or more than $200. They have varying features such as voltage (AC/DC), Continuity (a tone or visual signal tells you if there is a proper electrical path or cicuit), Resistance (ohms) and sometimes a temperature probe, Duty cycle, pulse width, memory store/recall, min/max/avg, etc. Of course, the more features, usually the higher the cost.

See: http://en.wikipedia.org/wiki/Multimeter

It's best to get a digital multi-meter because the analog type can damamge some micro-electronics because of the higher voltages they use, also DMMs are usually easier to use (read).

There are many mfrs. of DMMs, with Fluke probably being the best, though Siborg, TPI and Protek are all excellent as well. I have a $10 cheapie which stays in the toolbox and a better Fluke which cost about $60.

You can find them at any lowes, Ace, Menards, Home Depot, etc. as well as many online sources. It's a pretty valuable tool to have for the home, car, stereo, computer, etc.

BTW, you can also use a DMM to check a bulb or fuse using the continuity feature.

jhandy · 09-19-2008, 09:57 AM

Well the problem was the light switch. When rotating it to turn the lights the connection to turn on the lights would not connect and the car thought that only the parking lights where on.
New switch and no more worries.

Thanks to all for the help-you guys saved me money once again.

Wret · 11-04-2008, 05:24 AM

I'm having the exact same problem. Did you replace the switch yourself? I'm wondering how difficult this is.

koit · 11-25-2008, 01:50 PM

I'm also getting a no low beams issue. Both lamps.

How easy is it to replace light switch, is it a dealer scenario !?

jhandy · 11-26-2008, 05:27 AM

Replacing it is easy as long as you are double jointed and a skinny fellow. You have to reach behind the dash to the backside of the switch and there is a nut, this hold on the switch. Then just unplug and plug in a new one.
The switches are not expensive and can be bought from eBay for about 15$.