2002 porsche boxster new stereo car won't start

The person before me installed a horrible amp and kenwood deck so I purchased a new deck took out his kenwood and car won't start. Everything on dash lights up. Windows won't go down with key in on position also. I haven't tried to install the new stereo I have to figure out what this guy did. But the fact it won't start has me in full panic mode. I even tried spare key to make sure it's not a defective key chip. This is the mess i have to salvage. Thats with key in start position

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So to add to this. After trying everything with stereo wiring I decided to remove the immobilizer from under the driver seat. It came out really easily so I thought maybe plugs were loose. I put it back in and bam car started. So I bolted in seat and tried again and nothing. Back to square one. Dash lights come on but won't turn over. And can't put windows down or open hood / trunk. I'm at a loss.

I would suggest chasing the wires and check to see if the PO's stereo install cut some wires. My thinking is, with the stereo installed the circuit was complete, but when you took it out the circuit was cut. I would also go back to the immobilizer and check the install and chase those wires looking for something similar. Maybe someone else will have a better idea, might be something with the switch?

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So basically what you're saying is that the car worked fine until you removed the Kenwood system, correct? Unless someone else more knowledgeable chimes in, I don't think anything from the OEM stereo wiring is linked to the car's alarm/immobilizer on the '02 cars. I've had my stereo removed for service and the car started just fine without it. First things first, google the stereo wiring diagram online then begin to connect the wiring to your newer head unit. Be thankful, this is a non-MOST system and so you don't have to deal with fiber connectivity. After that's complete and tested, then move to the immobilizer problem. Check all fuses related to the alarm system. You may need to purchase a scan tool to zero in on the problem. But I would cross one bridge at a time. Good luck!

Apparently there is a ground wire on the left inside the dash that the factory deck makes a connection to. I was hoping to find the wire colour and what I should do with this wire to trick the car into thinking a deck is there. (I'm no expert just 4 hrs of google last night) problem is, last install guy cut it off the spot it should be and had it connected to part of the after market deck. But since his wiring was black tape garbage. Some wires came loose during uninstall. That said he also cut all speaker wires and had a ridiculous amp and sub setup wired in. So going strictly by porsche wiring diagram is not easy cause some wires are with amp some are with porsche. He cut the Porsche factory plugs off instead of buying adaptor and saving the factory setup. If I can find the wire to the stereo / immobilizer I could at least ease my mind that it is wired or covered or whatever then go to plan B. I fear I may have to take out both seats. And both door panels and remove all his wiring and see where I'm at after that. If I can get car to start I'll drive it to a stereo place and bite the bullet but I need it running. But like I said removing the immobilizer from under driver seat and just reattaching it cause the car to start once. Before going back to anti theft mode. Which is super weird

You might get better replies in the 986 (Boxster) forum, but for the 996, I believe the ground wire to the radio frame is brown.

I was in such a panic I didn't even notice. Lol. I did read brown and I was searching for brown. Then read green so I started looking for green. There is a green one there but it's been skinned by last install guy which leads me to believe it was attached to a power or ground but again. I don't know. To terrified to experiment

That is quite a mess. My thinking is that the immobilizer was tied into the Kenwood unit, somehow, and now the car is immobilized. I sure hope you pulled the fuses for all that, or have the battery disconnected. In that mess of wires, see if you can find a brown wire and attach it to the frame...but I'm also not sure that will work to un-immobilze the car. Sometimes it needs to be grounded, and sometimes not with aftermarket systems. Trial and error.

So I have been lost for days. No trunk control no power windows and of course just dash lights no start. This morning bored I sat in car to cry and I decided to hit hood latch and it worked. First time in a week. So I tried starting it. Also worked. Now I don't want to turn it off. But what would cause anti theft immobilizer to shut down features on Saturday but work Sunday. Now I'm really lost.

Quick update So I drove the car for about hour around town but never shut it off. I'm sitting in a parking lot with car on. I cannot put up windows or open trunk / hood. It's gone back in immobilizer mode while car is on. The odd thing is the hood / trunk dash light is on. That's what gave me a sign there was a problem. So even with car running it will immobilize itself. Hopefully I can get home.

Loose connection or wire has a short in it? Have you touched any wires that might have moved the angle of wire or jostled the connection? Run through the last few actions you completed and see what you touched. Is it possible the ignition switch is going and when you turned the key this time it shifted something around in the ignition switch?

Yes I had lost the only key I owned so the immobilizer was shipped to states and had to get a key programmed. So both keys are brand new with new programming. The immobilizer was reinstalled under seat and worked perfectly. Once the car stopped working the other day I removed seat and looked at immobilizer for water damage and all was fgood and put it back and the car started first try. Then I shut it off and wouldn't start for 4 days. Then I tried randomly today and started fine. Now an hour later it's messed up.

What about your ignition switch, is that new too?

No. It's all factory. Literally the only thing was taking out immobilizer over winter sending it for reprogramming and reinstall. Took about a week. Got it back. Two plugs to install bolt seat and it fired right up. Drove it home from storage and then hell began. And I have tried the plugs they are in tight. And I have tried gently monkeying with key in ignition moving it around to various angles. Nothing. I cant get over that while driving it actually goes into lockout mode. That's messed

Cant a bad ignition switch cause all kinds of weird electrical issues? Maybe im way off but it may be unrelated to the stereo or immobilizer.

OK folks. I MAY have found the problem. The trunk open indicator came on while driving which means it's locked me out. So when I got home I shut it off and sure enough couldn't start it. Decided to take whole seat out of car and while I was unbolting seat the indicator light went out. Great sign. Turns out the guy I paid to do install of immobilizer crimped a wire under the seat rail. So I took whole seat out cleaned under seat re did the connections bolted down immobilizer and re installed seat. So far flawless. I just wanted people to see my solution maybe it'll help someone one day.

I hope that was it and you can get back to driving.

Velly interesting story. I think there is a moral here. Sounds like you know more about the immobilizer and stereo install than the guy who did it.