Boxster won't start! Funny symptoms - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Hi all, I've been reading this forum for the last 3 happy, trouble-free years of owning my 2001 Boxster S, but unfortunately now have cause to ask for help! My Boxster won't start. Everything lights up, but it won't crank. I've had a funny few symptoms over the 24 hours running up to this, and I'm wondering if they might be related, or completely coincidental. Yesterday, my window winder mechanism packed in. The motor sounds like it's crunching. I've stopped using the window, but obviously every time I get in and out (or put the roof up or down), it's trying to use the motor, so 'crunches' a bit. On the way home today, the car was going really well. I got stuck in a traffic jam for quite a long time, but had the roof down, and heater on full blast. During this time, the radio suddenly stopped working (it had the power to eject a CD, but won't switch on). Also, my airbag warning light came on about the same time. I've had problems with this in the past, but these were fixed (until today apparently). The rest of the journey home was fine. I put the hood up (cue window mech crunching), and switched the engine off as normal. I then decided to see if I could get the radio to come back on. At this point, the engine would crank, cough into life briefly, and then not start. Wondering if everything had just got a bit hot (traffic jam!), I left the car to cool down. I went back to it later, and now, it won't crank at all. All the dash lights come on as normal at key position 1, but the only noise I get at the 'crank' position is a tiny little click behind the ignition key (relay in the dash somewhere?). I thought I'd disconnect the battery to see if anything would reset. Now, I knew about switching the ignition on before disconnecting the battery, so I did this. However, the alarm still went off, (siren only, no horn). I'm wondering if I have an immobiliser problem? I've tried connecting a (known good) battery in parallel but it made no difference. Any other opinions on what to check would be very gratefully received! I have a multimeter but no digital diagnostic equipment. Thanks in anticipation!

Could it be the ignition switch? I've read other threads on this forum stating the switch can cause strange electrical symptoms.

You need to remove the battery and install a good known replacement. Connecting a good battery in parallel with your existing (questionable) battery doesn't always work as a poor performing battery can compromise the donor. With your multimeter, check the battery voltage across the terminals - you should see at least 12.5v without the engine running. To check the alternator output, with engine running you should see at least 13.5v at the battery terminals.

You heard from the US and Australia so lets add Canada to the mix to solve a UK dilemma. Did the floor under the seats get wet by any chance? The electronics under there are vulnerable. If i am wrong maybe someone from the continent, or Asia, or South America can help. This forum really is the United Nations of BoxsterS.

There is a corroded/loose ground/earth connection in the erratic circuits. Probably where rainwater has puddled? Whatever, it is often recommended to drill a drain hole underneath the imobiliser and wrap it in ziplock bag.

Thanks everyone. Battery standing voltage is 12.0 Volts! I will pick up a new battery this afternoon and report back. I'm surprised it's the battery (it's been fine all winter) but obviously 12.0 volts isn't right. I wonder if I have a charging problem, or if the battery is just dud and all the traffic jam and heater motor load yesterday just tipped it over the edge. I guess that would explain why the radio stopped working and the airbag light came on. Will check for dampness too. I think she's pretty watertight but the drain hole sounds like a good idea.

Don't forget to turn the ignition to position 1 first before disconecting battery so you don't go deaf.

Hi, i think your battery is dead and one or two cell circuits died. Pretty common problem. To check if the generator and voltage regulator are working correctly, please start the engine (hope it starts with the new battery) and check the voltage. Voltage should be 13,8 volts if the engine is running. If not, there can be another problem. Regards, Markus

Thanks all. I've now fitted a new battery, but it still won't start. Even with the ignition switched on, the alarm still goes off when disconnecting the battery. I think the old battery being only at 12.0V is a clue as to what's going wrong. Not really sure where to go now; guess I'll have a look for any signs of immobiliser dampness, and will try and jack it up and have a look at the engine bay earth points for the starter motor. Any other suggestions without resorting to swapnostics or a flat bed? Thanks!

1.) Check all fuses. 2.) Check immobilizer below drivers seat. Wet or blown fuse (use forum search). 3.) Check ignition switch (use forum search) 4.) Check if starter gets electricity when you try to start. 5.) Put car on OBD diagnosis and check if you got any errors. Regards, Markus

Thanks Markus (and everyone else) appreciate that. Will start working my way through it...

The click he hears when turning the ignition probably is the Starter solenoid engaging, which is good. Perhaps good to check if the starter is getting voltage to turn...could a push start help to eliminate issues with engine...and hone in on the starter or other areas?

The infamous "Y" connector is corroded ?

Gelb - is there a Y connection on Boxsters? I thought it was only on the 996's. I don't remember seeing one when I replaced my starter motor and alternator, but maybe time & age is creeping up on me (more).....

Hi all, This is fixed; just thought I'd feed back in case anyone else gets the same symptoms. We found four blown fuses, including those on the immobiliser, which seemed to be a combination of the result of the window constantly trying to wind up (duff regulator), and something going wrong with the stereo. I guess the battery was naturally aged, voltage dropped, and the current (for whatever circuits) went too high as a result. Thanks everyone for your contributions! Regards, James

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Hello James, By any chance do you know if the blown fuses where the High Amp fuses? like the ones on the picture below? [/QUOTE]