Car won't turn over
 

Hello, I have a '98 manual Boxster and last weekend I was working on replacing the front speakers and adding a Bluetooth module to the HU. I started and ran the car several times during the day but when I was done installing the HU and speakers and tried to start the car, the car wouldn't turn over. I did the following...

• Checked the relevant fuses (B8, C1, C2, and C4)
• Jumped the clutch safety switch
• Jumped the starter relay in the rear trunk

In the end, I tested the battery and it was lower than 12V, so I pulled the battery and put it on the charger. I just reinstalled the battery and the car still won't turnover. I can hear the fuel pump turn on. I hooked up Durametrics and it had a number of codes associated with the battery being disconnected. I cleared those codes and the only code that remains is P1602: Supply voltage. Open circuit.

My battery is only 2 years old - so I would be surprised if it is a bad battery. I did a search in this forum but didn't come up with anything useful. Any recommendations on how to debug? I have had this Boxster for a couple of years now and it has been super reliable once I replaced the ignition switch and fixed the micro switches and door latches.

I guess I should add that I had the HU disconnected and the front trunk amp disconnected while working on the stereo - I really doubt that is my issue with the car not starting but figured I should mention this - as I know the HU is connected to the alarm system I believe.

Pretty obvious that the not turning over is linked to your work on the speakers .... HU.
If you have an "open circuit" code then you most likely have a wire disconnected or the battery is disconnected.
Go back in and triple check your work. the problem is in there.
Also check your battery connections....connection of the negative cable at the body.....and the positive connection in the little box by your power steering filler neck.
Clear the P1602 code and see if it returns.

I highly recommend getting a lion jump pack.

I find Boxsters are hard on batteries. Just vampire drains.

That being said. What exactly do you mean by wing turn over?

Starter turns, won’t fire?

Or no engine rotation what do ever?

If you turn the key and it won’t turn over
It’s either the battery, or sometimes the ignition switch.
The clutch pedal switch also comes into play.

If it turns over, but not fire, it’s typically immobilizer, fuel, or crank position sensor related.

I might have missed a few others, but this is a good start.

Mike

No engine rotation. I already jumped the clutch pedal switch to rule that out and I actually replaced the entire ignition assembly about 2 years ago with a genuine Porsche assembly (before I knew about the cheap way of just replacing the electrical switch). I'll retrace my steps working on the radio but other than the radio ground that is hooked up the the alarm, is there anything in the radio area that can cause this?

@blue62 - when you made this comment about the car not turning over being related to my work on my HU, I couldn't imagine how - but you were correct. Before I figured out you were correct, I tested the clutch pedal switch again, tested the battery, which is only 3 years old and tried jumping it from another car to rule out the battery. I then hooked up my Durametric again and got the codes Airbad B05 - 1, Alarm i32 - 25 W lead, and Alarm i48-25 short circuit to B+. Based on this, I found this thread: https://986forum.com/forums/diy-project-guides/60245-durametric-alarm-fault-i32.html

Based on this thread I checked fuse E1 - it was difficult to see that it was blown, but it was. I replaced the fuse and the car started right up!

When I was replacing the HU with the Bluetooth module plugged in, I had a heck of a time getting the HU back in place. I shoved it in and the Bluetooth no longer worked. I removed the HU again and saw that all the wires for the Bluetooth module ripped out of the plug. My guess is this is what fried that fuse, but when the next break in the rain happens, I'll put the head unit out again and check all the wires.

I'm in the Bay Area and I was really concerned that the alarm got wet with all the rain we have been getting (although everything felt dry in the car).

What is the easiest way to guide the head unit wires while you are sliding in the HU? Is it taking off the side panels in the footwell or removing the plastic panel to the left of the HU/HVAC?

Glad you figured it out and glad you posted the follow-up.

Classic, what have I touched lately!

I have a 2000S the footwell panels in mine just pull out so that would be an easy place to start with to see if it helps.
You can pull it back out then with a flashlight and favorite beverage just sit there and look at it for a while. Look at what has to go into the space versus the size of the space. Look at the wiring and connectors. Look at what will trip you up. What can the wires hangup on. Mentally put everything back in place. Then most times it will physically go back together with fewer issues.

If your going to work on something electrical it can pay to disconnect the negative battery cable while doing the work.
Doing this can save burned fuses burned wires or even fires in some cases.
It is easy to short a wire or cause a short to ground with a screw driver or wrench.

Sometimes you can't see a bad fuse. It is better to use a little circuit test light and test it in place.
The test light has a sharp pointed probe at on end and an alligator clip at the other.

Yes if you have issues after just completing some work or recent work.
Always retrace your steps the problem is almost always where your hands were ;)

All great advice! For some reason, replacing speakers and adding a Bluetooth module to the radio didn't seam like enough to disconnect the battery, but lesson learned!