scottjk

I have a 2003 Boxster S that has been plagued with electrical issues since I bought it.

Most are intermittent like the soft top not opening and closing and the radio not turning on or off. Those generally fix themselves.

Two days ago the interior door lights and dome light won't turn off. The alarm won't set. I get the single horn beep indicating that some part of the system is not secure. The drivers window does not retract when pulling the door handle. It does retract when opening the soft top latch. I have tested the micro switch in the door handle and it appears functional according to a multi meter continuity check.

It appears to me that it's the drivers door lock mechanism not indicating the drivers door is closed. I have read to many threads that guys throw money at a new unit that does not fix the problem and in some cases causes more problems.

Passenger side appears to function normal. I do have the M535 option. Not sure the passenger side mechanism would have anything to do with this.

Thanks for the help!

Scott

Dave H.

a dealer, or a shop with the dealer scan tool can check the alarm system. that might show causes of the beeping and not activating.

Schnell Gelb

Scott,
When multiple,separate circuits malfunction simultaneously ,it is logical to find a common factor. The only one that I can think of is ground faults.
The solution is to start at the battery terminals an work systematically through checking for high resistance/loose connections.
Since you have done some research, you found the threads on corroded battery cables(invisible-inside the insulation) ? And the wet carpet under the seats = corroded electronics?
Not rocket science but just hours of careful systematic testing with a cheap mulit-meter.

JayG

check your ignition switch. It can cause all sorts of electrical issues

Schnell Gelb

Ignition switch is a common defect on older Bxstrs.
Here is the diy fix:
http://www.pedrosgarage.com/Site_3/R...on_Switch.html

Macster

Could be an ignition switch but I'm leaning towards the passenger door lock assembly being the culprit.

My Boxster would issue the beep upon locking with nothing ajar or open and the passenger window would fail to lower when opening the door, or worse lower then raise once the door was open, and the door locks would lock themselves after driving away.

Tech connected the Porsche diagnostics computer to the car's security system and checked for errors and checked some other things just to be sure it was not something else but all the fingers pointed to the door
lock assembly.

I don't know about other owners throwing money to have this replaced and being disappointed, but in my car's case replacing this passenger door lock assembly cured problem, eliminated all the symptoms.

Be sure the cabin floor is dry and there is *no* sign of water/dampness. Give both doors a shake to listen for water sloshing. Check the door bottoms for any signs of dampness.

Check the body water drains to ensure they are open and water drains without any problems.

You can replace the ignition switch electrical part if you want. The part doesn't cost much and the job is not that hard.

If it eliminates the symptoms then that's great.

My WAG is it will not but I hope I'm wrong.

PelicanParts.com

I doubt it's a single cause as those issues are spread out among a few different systems. You need to check faults in all control units. Then verify that all the micro switches and the windshield frame (forward latch micro switch) is working properly. I second the door lock assembly as one of the culprits. We have a DIY here that may help. As for the soft top, check to make sure the parking brake light comes on in the cluster when you pull up the lever. If not, check the switch in the center console as it could be dirty or broken.