Since a couple of days I have a strange thing going on. When I shut down the engine and remove the key the battery seems to disconnect so that I cannot lock the car. When I fiddle around a bit with the earth cable the battery seems to connnect again, I notice this when the trunk light comes on again. I checked the connection and all seems to be ok, when I move the cable around the connection remains ok ( the trunk light stays on). An y suggestions on how to tackle this problem.Tx.

 

What you describe sounds like an oxidized connector. It is possible for the connection to heal, because the starter current can weld across a bad connection. The problem is that the weld breaks over and over again, and eventually you have a no connection, or you overheat and have a fire.

Remove the battery cables and clean both ends. Scratching the faces of the electrical contacts with a sharp and clean wire brush is the best way to ensure lots of good clean contact points.

I am not sure what they sell in the EU, but we can use oily felt washers under the battery terminals, or spray various treatments on the terminals to keep them corrosion free.

This is a maintenance procedure, and should be done every few years to keep the problem from happening. Don't wait to have a problem next time.

 

Tx Springer, I removed the cable and didn't really notice any corrosion. I will nevertheless go over it with a brush. Can I use ordinary grease on the poles, I have some Lithium based Coma grease but I'm not too sure if this ok.

 

Just clean and reterminate the ground, use the anti-corrosion washer "thingies" available from any autoparts stores, they're green and red, usually and some type of "No-OX" compound where it terminates via the 8mm (13mm head) bolt at the tub/body...clean the face of the threaded insert and apply compound there as well.

 

Ok Jeff, thanks. I'll get that stuff tomorrow.

 

The corrosion will be oxidization of the lead round battery terminal post, and the INSIDE of the terminal post connector. You can see the grey oxide crud in your picture.
Or is it too much "Jack Daniels" and I 'm seeing things again!!
No No No..................Not the pink Elephants !!!!!!!!!!!!!!!

 

maybe it the Pink back panel and tail lights you see

 

If the trouble persists, replace the cable. The crimp connection between the end fittings and the copper cable can go bad. I have soldered crimped connections, and that prevents further trouble.

Your cable looks pretty good, so it is surprising you are having problems.

 

I looked at it some more just now and I noticed that the connector on the cable is not perfectly round and that the bolt is also bent. I'll take no risk and will just replace it. I didn't look very cool when I had to dive into the trunk before being able to start her again, just after filling her up at the gas station.
Thanks for all the replies guys

 

Couldnt have been any worse looking then when I had to be towed out of a gas station when my DME relay took a dump without warning a few weeks ago

 

For one of my previous cars (Honda), I cleaned terminals with steel wool and coated with vaseline -- worked well to prevent corrosion.

Marc

 

Kris... A wire brush or sandpaper will clean your terminals and posts in a pinch... But they make a battery terminal cleaner that looks like this...



You can see the different brushes that clean both the terminals and the posts. It's nothing but a round wire brush. They sell for about $5 USD in the auto parts stores around here. You'll use it maybe 10 times in your life... But it's great to have it when you need it!

 

Hi,
My original earth cable (like your in the picture) was the cause of all my battery drain problems for years. It also caused my battery to be flat and alternator to only charge the battery over 3-4 rpm's. I just replaced it and the problem is gone, a friend with an RS just did the same and fiixed his car also.
Mark

 

I installed the new earth cable and took her out for a drive. Everything seems to be ok and my idle and stalling problem which I encountered with the a/c on has vanished. Thanks again for all the help

 

I don't know why P cars are so sensitive to earth cable issues. I had similar problem and the sevant, who is my mechanic, insisted in replacing what appeared to be a perfectly good cabe that was not a Porsche part with a new Porsche cable. Worked like a deam thereafter.

Jim