helispud

After 5.5 years my battery went dead. I think that keeping it on the maintainers jut forestalled the inevitiable.

Any how we were ready to leave and ...not enough cranking to start.
I opened the hood and battery compartment to attached the big charger. The compartment was a mess with corrosion acid all over including the compartment lid. As I am 180 miles away from the closest dealer I went to our local Les Schwab dealer who actually had an 94R battery in stock I thought about just getting the battery and going back home to install it at home but we were heading out of town and home is 15 miles the other direction. So I let the tire shop guys start the install. I was feeling ok because the best guy and owner were working on my car. All was going well..we cleaned out the compartment and flushed it with water..the battery was a perfect fit..but just as they were hooking up the cables I noticed the battery was backwards. Yup, negative was pos, and pos was neg for enough time for a spark.

The battery was then spun around,and the car started fine the PSM light went off we reset the windows, etc. so all is good. But a few miles down the road I,touch thebutton toturn on the radio..dead. So I stop and check fuses.the 25 amp for the bose amp is blown but the PCM fuse (10 am) is good. After a 2.5 hour drive to our destination I spent the time to check all the fuses and all are good.
So..did I just have the moat expensive battery replacement ever?

(excuse my typing, I'm doing this on an iPad.

helispud

I forgot to meant ion that when I checked the battery 5 weeks ago everything seemed fine, no corrosion everything clean, all was good.

mattyf

I'm hoping it's just the Bose fuse. Fingers crossed. Keep us updated.

McCulla

Seems odd that 5 weeks later there is this much change in the battery compartment. Charging system issue as well?

helispud

I have replaced the Bose amp fuse but thePCM is still dead. It will probably late next week before I can get the car to the dealer.

McCulla, yeah, the battery had the look of being overcharged.

Jason Judd

If your PCM is dead, as mine was a short time ago, I suggest you send it to Becker Autosound in NJ. They will repair it for about $750 and warranty it for 1 year.

On the other hand, you can buy a new unit from Porsche for a million dollars...or, something close to that price.

jfoxny

This is the normal expected lifetime of the battery regardless of if you use a maintainer or not. So, you did nothing wrong on that front.

Chris from Cali

On a serious note, will the PCM from the 997.2 fit? If you do replace it, the upgrade would be worth the money...

Mark Harris

I recall reading here or another fourm that it's pretty complicated. Not an easy plug and play swap between .1 & .2 like one would hope.

Only going on memory and hope I'm wrong because .2 is a huge improvement over .1

Jack667

You could also consider a Kenwoood or similar head unit. I did this, even when my PCM was fine. I sold it cheap. So - either look for used pcm's that someone removed for an aftermarket head unit or do the 'smart thing' and put in the aftermarket unit!
I have bluetooth phone capability, DVD, sat radio, iPod hookup, Garmin nav, backup camera and more.

JCGMS

This battery reversal and dead PCM scenario happened to a 997.1 I was considering buying after the dealer agreed to install a new battery for me. Unfortunately, it killed the sale too. I believe there may be a fuse in the back of the PCM itself (not the fuse box one) that will fix the issue.

Zeus993

You can have mine. Jst kidding but I love the sound of the engine and hardly ever listen to it. I would spend money on a new exhaust before that and really only repair it if I was selling the car. How much do you listen to it? Becker Auto sounds like a great alternative.

USMC_DS1

I've considered installing the Kenwood unit as well. Does it allow you to access all the p-car menu items and settings available with the PCM?

Jack667

Unfortunately not. None of that is available through an aftermarket head unit. I replaced mine soon after purchasing my car, so I don't even really know what I'm missing. I use Sport Chrono timer as a gimmic, using the stalk. I dont need to change DRL settings.

helispud

I hardly ever listen the radio/cd player either. My wife and I just got back from a
1200 miles 3 day weekend (Washington Wine Country tour put on by the INWR PCA region) and really didn't miss it at all. I did miss the trip info though. I agree the only reason to replace would be to sell the car.

When I got home I pulled the battery out to remove the tray and do a cleanup of the whole front of windshield area. Tomorrow I will sand the corrosion/rust off the battery tray and repaint it. When I hook the battery back up and reboot everything again maybe the PCM will come back to life.