MAKING ALL THE RIGHT CONNECTIONS
I have always enjoyed modifying cars to make them more reliable, rather than merely more powerful and/or ‘faster’ – and which all too often ends in tears. I have long believed, too, that the most valuable upgrades often come from enthusiasts who use their hard-won experience and occupational expertise for the common good, rather than to make a quick buck. They come up with realworld answers, in other words, not solutions looking for possible problems.
You will understand, then, my interest in a Facebook post from 968 enthusiast and 911 & Porsche World reader David Cunningham of St Peters, Missouri, USA – a district of St Louis. Seems that David was in the process of changing the timing belt on his own car, and discovered that the starter motor and generator wiring had deteriorated badly – an increasingly common problem, and although not necessarily as widespread on the older transaxle cars, with arguably slightly better-quality wiring, by no means unknown.
‘The insulation on the 968’s original alternator-tostarter wire has a reputation for breaking and crumbling over time,’ writes David, ‘causing all kinds of problems, including shortcircuiting to the solenoid wire and/or causing fires. I decided that to replace the original harness on my car with another of the same would be pointless, because the same thing would happen all over again.
I work in an electrical prototyping laboratory, though, so I knew I could easily fabricate a more reliable and longer-lasting set of wires than the original Porsche harness.
‘So my alternator-tostarter cable is made of
TEMCO Industrial 4 AWG Epdm-jacketed welding cable (150 amps/600 volts) with tin-plated, marine-grade lugs at both ends. The starter solenoid wire is 10 AWG Gxl-insulated (125 degrees Celsius) automotive primary wire, and the alternator exciter cable is Southwire 18 AWG Sxlinsulated (85 degrees Celsius) automotive primary wire. The exciter wire’s ring terminal at the alternator is made of stainless steel to prevent corrosion.
‘The terminals on my solenoid and exciter wires are both crimped and soldered. The standard Porsche harness does not have soldered terminals – they are simply crimped. I covered all ends with double-layer heat-shrink, with one sleeve over the terminals themselves, and another sleeve retaining the ends of the PET sleeves used on all of the wires.
‘On my wires the female connectors that plug into the main harness are from the OEM Porsche supplier. The plastic socket on my wires is from the OEM supplier, but they have changed the shape to straight walls instead of the slight taper that the old ones have. They should still fit, though. Both connectors had to be sourced from overseas – one from the UK, the other from Brazil. The length between eyes on the alternator-to-starter cable is 48 inches (122cm). The length from the ring-terminal eye to the end of the plastic socket connector is 36.5 inches (93cm) on the solenoid wire, and 45 inches (114cm) on the exciter wire. The lengths were carefully measured from a used original harness.
‘Several of my friends on Rennlist’s 968 forum liked what they saw and wanted them, so I made up four more sets. They have installed them and report that they work well, which is the same experience I had. That made me realise that there must be a market for these harnesses, and so now I offer them for the various 944 models, too: 2.5, 2.7, Turbo and S2. Those are all slightly shorter than the 968’s – and there is also a difference between 1985 and 1986 models, so I need to know which car they are for. For all of them, the price here in the US is $120 including first-class shipping, and for overseas $115 plus whatever the actual cost turns out to be.’
Interested? (And if you are a transaxle enthusiast who doesn’t wish to see your car self-destruct then I think you should be.) For more details have a look at David’s Facebook page – he’s easy enough to find – or send him an e-mail at dcmachinist@att.net.