I have enjoyed a few "starting" issues over the years and with a modicum of electrical knowledge I have got it wrong on occasion, as mentioned in my initial response above. One failure was on my SC in the car park of a hotel on the island of Arran... where removal of the starter motor and quick clean up resolved the issue. using the Porsche supplied jack, the removed rear wheel placed under the SC and a milk crate to ensure a minimum degree of safety...!!!
I suspect best not to think anything less than 12 volts might be a good starting point... No pun intended...(-: For sure a solenoid on it`s own and in good condition may pull in against it`s internal spring at a lesser voltage than 12v, but in reality a battery measuring less than 12v off LOAD, may drop voltage as soon as the ign is switched on, and further still as you turn the key to the start position, thus increasing the LOAD on the battery along EVERY connection on it`s way to feed the starter motor ... ?
There are rather a lot of connections in the starter circuit of an air cooled Porsche, even discounting anti theft devices, any one of which can create a no go situation, if loose or cruddy.
If you get as far as a chatter from the starter motor as the solenoid clicks in and out, that is indicative of a drop in voltage at the starter. i.e. enough voltage for the solenoid to pull in, which on doing so switches the starter MOTOR into circuit, and which in turn increases the load on the circuit exponentially, to the extent that any dirty or loose connection will induce VOLTAGE DROP at the starter in the form of producing heat at the location of the crud... and even if the wiring and all it`s connections are perfect... A battery which measured 12 volts may drop it`s voltage on initiation of the start command, to the extent that it does not have enough POWER to perform a start.
I could go on but will stop there, unless anyone cares to take the discussion further.
p.s. I claim ZERO expertise.
I suspect best not to think anything less than 12 volts might be a good starting point... No pun intended...(-: For sure a solenoid on it`s own and in good condition may pull in against it`s internal spring at a lesser voltage than 12v, but in reality a battery measuring less than 12v off LOAD, may drop voltage as soon as the ign is switched on, and further still as you turn the key to the start position, thus increasing the LOAD on the battery along EVERY connection on it`s way to feed the starter motor ... ?
There are rather a lot of connections in the starter circuit of an air cooled Porsche, even discounting anti theft devices, any one of which can create a no go situation, if loose or cruddy.
If you get as far as a chatter from the starter motor as the solenoid clicks in and out, that is indicative of a drop in voltage at the starter. i.e. enough voltage for the solenoid to pull in, which on doing so switches the starter MOTOR into circuit, and which in turn increases the load on the circuit exponentially, to the extent that any dirty or loose connection will induce VOLTAGE DROP at the starter in the form of producing heat at the location of the crud... and even if the wiring and all it`s connections are perfect... A battery which measured 12 volts may drop it`s voltage on initiation of the start command, to the extent that it does not have enough POWER to perform a start.
I could go on but will stop there, unless anyone cares to take the discussion further.
p.s. I claim ZERO expertise.
