Robertf1997

Hi everybody, I have a 2005 Boxster base 2.7l 6sp manual with 103.5k miles. I have had a no start issue since December and have done a lot to the car to attempt a fix. Car has no modifications, original radio, lights, everything. I have taken the car to a Porsche mechanic of 40 years and he even seems stumped on this one.

Main issue: Attempting to start- put key in, turn to accessory, lights come on, steering lock releases, all normal stuff is ok. Try to turn the key to start and car loses all power. Dash lights shut off, key gets stuck in lock and won’t come out until car randomly powers on hours later and releases it. Every time I replace an electrical component (battery, starter, alternator) the car will work perfect for a day then the same issue happens.

What I have fixed- all connections at battery cleaned with wire brush as well as connections at starter. Battery replaced first thing. Then replaced the alternator because it tested bad. Car worked fine for a day after alternator replacement. Then replaced starter motor. Again car worked perfect for 1 day afterwards then back to main issue. Car also has 2 extra grounds to frame on negative battery terminal.

Mechanic seems stumped and has never seen anything like this in his 37 years working on porsches. He suggested we try another new battery and an ignition switch. Gave him the green light for that but he didn’t seem like he thought it would solve the issue, just a good first step he said.

Attached is a video of my issue I uploaded to YouTube. PLEASE WATCH UNTIL END! Only 30 seconds. Issue happens at 22 seconds mark

It will show the entire issue.

I appreciate any and all suggestions, I have searched the forums for days and days and slightly similar issues seem to be solved by a starter relay (7), ignition switch, immobilizer, ECU replacement, battery cables themselves, cable from positive terminal to starter however I am fixing this on an ICU nurse salary which means I can’t afford to keep throwing $500 Bosch parts at this thing. Any and all suggestions would be so helpful. Thank you everyone!

Joan Alcover

Looks like your battery needs full recharging and, if this is not enough, replacement.
You have done that, and replaced other parts; despite these actions, battery dies after one day.
So you must have a short-circuit somewhere that drains the battery in one day.
My suggestion:

• Put the battery (it is "new", right?) on a "battery maintainer/charger" to fully recharge it;
• Once the battery is fully charged, start the car; it should fire up.
• Then leave the car 24 hours without touching it;
• Then try to start the car again; if it does not start, it is clear you have something draining the battery: some form of short-circuit or "very parasitic load".

One odd thing I observed in the video, the fuel gauge remains "connected" even when all the dashboard lights go off!
Also, how good are the "2 extra grounds to frame on negative battery terminal"? What is their purpose? Could they be the source of the battery drain? Have you tried removing them (temporarily)?

cmassler

Do these cars have a DME? I had some really bizarre ‘running’ issues on a 944 I owned when the DME was going bad.

jscott82

So everything is fine until you try to engage the starter? Have you checked the ground strap from the angine to chassis? This just smells like a grounds issue. Sounds like your mechanic does too if he has added grounds from the battery.

The next thing I would try is connecting a jumper cable directly from the battery neg to the starter frame, see if that solved the issue. That would Co firm if its a grounding issue.

ZuffenZeus

I lean to the ignition switch being the problem based on the behaviors in the video and what I've personally seen from other owners of these cars. I think your mechanic is going in the right direction. Hope it works!

mytime1

I know this is going to sound like a dumb answer, but I had something similar. I would turn the key and car would not even try to start. (My electronics stayed on though.) I found that if I pushed the key into the ignition a bit harder, it solved the issue. Haven't had an issue since over the past 6 months. Odd, not sure how to explain it.

qwe

The routine that your dash info is going through in the video does not seem the same as my 2012 BS. The example, at the very end, the clock resets itself to 12.00 from 12.01 and the fuel gauge stays on. Not sure where that leads to.

SpyderSenseOC

That all sounded great until you asked whether adding grounds could be the cause of the issue. It can't. You could add a million additional grounds without any negative impact.

Joan Alcover

You are absolutely right ..... if the grounding cable or mesh is installed properly; if it contacts a "live" wire (or part) on the way, then you might have a "negative impact" (from the unwanted connection to the positive).

Robertf1997

I’ve heard of this ground strap before and it seems like a good place to check regardless of whether the newly installed ignition switch solves the issue. Could you tell me exactly where to find it? I can’t find any images of it anywhere.

jscott82

Underneath the car passengers idle.

Robertf1997

A brand new battery was placed yesterday along with an ignition switch. As of now the car is working as it should but we will see. I wonder if the fuel gauge staying on was in fact the ignition switch keeping it in, or if it’s just a short and all power was lost, including power to put the indicator back to zero. I’ll keep everybody posted.

Joan Alcover

Any positive news?

SteveG

https://rennlist.com/forums/987-981-...-t-get-in.html
Post 26 in the above thread.

I don't know that the OP has ever done this, but I think it needs mentioning for anyone following along with batt drain issues that it is a no-no to leave the key in the ignition when car is parked and left.

alvitdk

First thing I do if that happens, turn off the car, put a DVM in 10 A Amperage mode between the positive battery terminal and the cable, basically in series to the positive cable, and measure the leaking current. Seems to me if it works for a day, you have some current being drawn when there shouldn't.