David Cunningham from Missouri is a Porsche 944 enthusiast who always thinks that there is a better way. His background in mechanics, machining and electrical prototyping helped him develop some needed wiring and cables for our cars. He submitted this article about what he is doing to help us all with our cars.
The David Cunningham Story…Better Cables
I always loved Porsches and finally bought my first one back in November 2019. It’s a 1995 Guards Red 968 Cabriolet with about 61k miles. I found that my original wires were in bad shape while doing my water pump, belts, rollers, seals, oil cooler housing seals, and cam chain and pads.
I needed a new harness. There was no way out of it. The insulation of the OEM alternator to starter wire is basically non-existent and legendary in its reputation to break and crumble over time causing all kinds of problems including shorting to the solenoid wire or causing fires.
I decided that to replace the original harness with another of the same was not in my interest. Since I work in an electrical prototype laboratory and knew I could make a more reliable and longer-lasting set of wires than the original harness, I made my own. Several of my friends on Rennlist liked what they saw and wanted their own, so I made up four more sets for them. So far, they are working out just fine.
The alternator to starter 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 cable ends are coated in dielectric grease before crimping the lugs.
The starter solenoid wire is 12 AWG GXL-insulated (125C) automotive primary wire and the alternator exciter wire is Southwire 18 AWG GPT-insulated (85C) automotive primary wire. The exciter wire ring terminal at the alternator is stainless steel to help prevent corrosion.
The terminations on my solenoid and exciter wires are crimped AND soldered, to ensure a long life. The Porsche OEM wiring harness that came with your car and the OEM replacements sold today do NOT have soldered terminals – they are only crimped.
I double heat-shrunk all terminations with one sleeve over the terminals and another sleeve retaining the ends of the PET loom sleeves. The bullet connectors that plug into the main harness on my wires are from the OEM Porsche supplier, though you will have to reuse your old plastic socket. Just depress the lock tabs on your old bullets, pull them out, and insert the new ones which will lock into place.
I did not use the factory routing of the wires because I didn’t like their routing (clipped right next to the engine under the intake), but these wires will run the original way. The length between eyes on the alt-start cable is about 48″. The length from the ring terminal eye to the end of the bullet connector is about 43.5″ on the solenoid wire and about 41.5″ on the exciter wire.
Main lugs are 5/16″ hole diameter. Solenoid wire ring terminal is 1/4″ hole diameter. Exciter wire ring terminal is 3/16″ hole diameter. I am working on a solution that will fit perfectly with the 924S and Series I 944, too.
Future plans involve replacement harnesses for other parts of the car.
Thank you to everybody who has trusted me to supply wires for their cars so far. I build them as if they are for my own car every time. If you ever have a custom application, I am happy to help if I can.
David Cunningham
If you want to contact David about his cables, please use his email at dcmachinist@att.net.
