Ambient temp sensor and headlight problems

I have a 2006 Boxster S that stopped displaying the outside air temp. I replaced the sensor behind the passenger side grill, and it still reads -----. Now I noticed my headlights , side marker lights (front and rear) and fog lights aren't working. They come on for half a second when I switch them on. Relay, maybe? Tail lights and brake lights work. All the turn signals work. It has the Bi-Xenon headlamp package. I haven't used the headlights in months, so I don't know if this is a recent thing or not. My closest dealer is 3 hours away, so any advice is appreciated. Thanks!

Hi, welcome to Planet-9, the Friendly Porsche Forum.. I see this is your first post - but it's in the wrong spot - so I'm moving it.. hang on.. OK - done. ------------------------------------------------------​ There are no relays for the lights... they are all controlled by two modules - the front body control module, and the rear body control module. The modules in turn are controlled by the light switch in the dash.. which tells the modules when to turn things on or off. The headlights, fog-lights, front side-marker lights and front turn signals are all controlled by the front module. While your turn signals are working there is still a chance the module has issues. What are the "rear sidemarker lights" - on a 987 those are part of the taillight assembly. What makes this more confusing is - the ambient temperature sensor isn't working, even after replacement (and you DO really want that to work - the engine mixture is changed according to ambient temperature, and if it stops working you'll run a rich mixture - not a good thing in a car with potential bore problems.. washes the oil off the bores..) In chasing it in a wiring diagram - the sensor connects to the Climatronic control panel.. ie the HVAC control panel. The reading is converted to a CAN-BUS code and put on the car's computer network, making that reading available to other components. It has NO connection to the front or rear body control modules. OK - so first some simple troubleshooting - Check ALL the fuses. Have the battery tested. If you don't know how old it is - it may be worth replacing. These cars are very unhappy with low battery voltage. Find the front body control module and disconnect and reconnect it a few times. It's located (according to the service manual) on the right side of the front trunk, behind the inner lining. The disconnect/reconnect will work to "wipe" the contacts - if any are dirty that should help clean them up. Get a Porsche specific diagnostics tool that's capable of reading the "state" and input signals to the various modules. If the front body control module is getting a signal to turn the lights on (usually you can send that signal from the tool) and it doesn't switch those output on - then you know the module has an issue. Other than that.... electrical issues are a real challenge for many technicians. They're taught mechanic stuff, but they rely on a diagnostics tool that tells them "replace this part.." to solve electronic issues. When you have a chance - please visit New Member Introductions - and sign-in. Let us see pictures of your Boxster, and tell us a few things about your car history..

Thanks for the response and good info. I Taking the battery in for a test today. Checked each fuse with a test light first thing, all good. What is the easiest way to gain access the the temp sensor behind the grill? I loosened the screws on the bottom of the front bumper, pulled it down a bit, and was barely able to change the sensor. Maybe I pulled something apart, it was a tight fit. Gotta be a better way. I'll look for the module. When I bought the car 5 years ago, it had sat over a year with a dead battery . 14,000 miles, like new. But the seat heaters and headlight washers didn't work. I had to take it to the dealer so they could go in and remind the system that this car had those options. Independents didn't have access to that part of the system, so I might be back at the dealer. Thanks again.