Can a bad ignition switch kill power at the jump post?
12-06-2012, 10:47 PM
#17
Rennlist Member
Ahh... No. That is not a good test.
A bad ground strap or bad battery connection can look exactly like a bad battery (or not).
It can also be bad (as described) and most of the time can work quite perfectly - so no test like this is in any way conclusive.
You must directly test and flex the strap while testing to evaluate for this failure mechanism. It is quite counter intuitive - I know - but yes a big thick strap can actually be a conductor one moment and an insulator the next...
Alan
A bad ground strap or bad battery connection can look exactly like a bad battery (or not).
It can also be bad (as described) and most of the time can work quite perfectly - so no test like this is in any way conclusive.
You must directly test and flex the strap while testing to evaluate for this failure mechanism. It is quite counter intuitive - I know - but yes a big thick strap can actually be a conductor one moment and an insulator the next...
Alan
It could be dumb luck.
12-06-2012, 11:00 PM
#18
Rennlist Member
The 928 ground strap is an oddity Ive certainly never ever had to deal with in its odd manner, on any other car before.
12-06-2012, 11:09 PM
#19
Rennlist Member
12-07-2012, 12:06 AM
#20
Nordschleife Master
A bad strap also prevents even a good battery from being recharged. Half the time with a 928 the battery is getting weak and the ground strap is also corroded, so it may be a toss up which is the dominant issue depending on how the ground strap gets wiggled or was last wiggled.
12-07-2012, 12:24 AM
#21
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Resistance increase in the battery (bad battery) looks exactly like an increase in resistance anywhere else in the circuit, like at terminals, ground strap or anywhere else - no simple load test can distinguish between these...
Ergo - It was luck
But batteries fail more often than anything else - so its always the most likely answer - No feud required.Alan
12-07-2012, 12:47 AM
#22
Rennlist Member
My ground strap is OUTSIDE my charge circuit - direct from a socket on the bumper cover (under the licence plate) to the battery poles , with a 10A fuse in the positive line. If the charger says its full, its pretty much going to be true. I can also disconnect the battery from the car to work on things (like the pod), or for extended periods, like a new tank and hoses etc, but keep the battery happy.
jp 83 Euro S AT 54k
jp 83 Euro S AT 54k
12-07-2012, 09:04 AM
#23
Rennlist Member
My ground strap is OUTSIDE my charge circuit - direct from a socket on the bumper cover (under the licence plate) to the battery poles , with a 10A fuse in the positive line. If the charger says its full, its pretty much going to be true. I can also disconnect the battery from the car to work on things (like the pod), or for extended periods, like a new tank and hoses etc, but keep the battery happy.
jp 83 Euro S AT 54k
jp 83 Euro S AT 54k
12-07-2012, 05:08 PM
#24
Rennlist Member
Too true, didnt consider that side of things. As soon as I have any issue that might relate to that I will test the strap. So far, so good!
jp 83 Euro S AT 54k
jp 83 Euro S AT 54k
