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The factory wiring diagrams will have the wiring gauge in mm2. From there you could convert that to AWG. I wouldn't worry about trying to match it exactly, as there are probably several different gauges in use behind those circuits. I'd just make sure it's at least the size of the factory wire and when it doubt, go one size up. You should be able to eyeball it.
As for splicing the wires, I'd encourage you to not use solder for this application. It's counter-intuitive, but wiring harnesses typically use crimps for splices and terminals for a reason - I've been told they hold up to the vibration of a car better than solder.
The factory wiring diagrams will have the wiring gauge in mm2. From there you could convert that to AWG. I wouldn't worry about trying to match it exactly, as there are probably several different gauges in use behind those circuits. I'd just make sure it's at least the size of the factory wire and when it doubt, go one size up. You should be able to eyeball it.
As for splicing the wires, I'd encourage you to not use solder for this application. It's counter-intuitive, but wiring harnesses typically use crimps for splices and terminals for a reason - I've been told they hold up to the vibration of a car better than solder.
Thanks. Good info. I have the workshop manual on my computer and the bentley version as well. I'll check. I didn't see any mention of size but admittedly I looked quickly.
Crimping is easier so that is good to know as well.
--Michael
As stated by others, the wiring for those switches all varies in gauge thickness. For instance, the sunroof switch wires are much thicker than rear spoiler switch wires —- I got really intimate with these wires when I redid my interior as well. One approach you could take is ask a Porsche dismantler (I approached Parts Heaven in California) and ask them to cut all the switch sockets from the center console of a wrecked 964/993 with at least a a foot or two of wiring stll attached. Then you would just remove your existing sockets and solder or crimp on the 1-2 foot extensions with sockets attached, and wire gauges thicknesses perfectly matching. Good Luck.
As stated by others, the wiring for those switches all varies in gauge thickness. For instance, the sunroof switch wires are much thicker than rear spoiler switch wires —- I got really intimate with these wires when I redid my interior as well. One approach you could take is ask a Porsche dismantler (I approached Parts Heaven in California) and ask them to cut all the switch sockets from the center console of a wrecked 964/993 with at least a a foot or two of wiring stll attached. Then you would just remove your existing sockets and solder or crimp on the 1-2 foot extensions with sockets attached, and wire gauges thicknesses perfectly matching. Good Luck.
Crimps are only better than solder when the correct tool for the crimp is used and the correct crimp for the wire gauge
otherwise solder and heat shrink it very reliable here
Crimps are only better than solder when the correct tool for the crimp is used and the correct crimp for the wire gauge
otherwise solder and heat shrink it very reliable here
This. Soldier and heat shrink is FAR superior to crimp type connections like those used in cars. The cheap plastic butt splices are NOT a superior way to do this. Crimping can be VERY reliable when used with a proper tool as a termination type connection. Even in aviation applications with far more vibration, only heat solder splice environmental connections are authorized. There is a reason you won't find a single one of those crimp type butt splices on any car from the factory.
Have you pulled the harness all the way up off the console and up toward the radio plate? I was able to relocate the switches in my 964 without any splicing (excepting the wire for the handbrake light switch), and the 964 wiring configuration is largely similar to the 993.
Jim
Harness (coated in rubber ) runs straight up to the radio plate leaving a few spare inches Here's another angle (the wire wrapped around the steering wheel is the new handbrake brake-light wire spliced off the harness)
Harnesses are the bane of any automotive modifiers existence. The bulk of wiring work done by even so called quality workshops is questionable. I would avoid hacking into you harness if at all possible. The harness as comes from the factory is most reliable and is only factory once. If you can avoid cutting it to lengthen it this would be best. I've gone to the extent of making patch/extension harnesses with factory connectors on each end (like an extension cord) just to avoid cutting off connectors if possible. If you have to hack you harness here are some pointers:
- Use proper GXL/TXL wire. Cross linked polyethylene insulation is factory spec. The cruddy wire they sell at autoparts stores is PVC insulated and is far inferior. mpruden is correct that Porsche wire is all metric and difficult to source in the US. You can substitute AWG for most. Typically 18Ga or 20Ga for most under dash harnesses. I go to the trouble of matching insulation colors including striped/solid colors. This means you end up stocking a pretty wide range of wires.
- Never ever solder terminal connections. Never. Ever. Factory harnesses are crimped for a reason. Crimp connections are most resistant to vibration and flex. A proper crimp terminal pretty much cold welds the terminal and copper strands. If you section it on a bandsaw, it looks like solid metal. Solder wicks up multistrand wire and turns the end effectively into solid core wire which does not flex. The junction between solder affected wire and the normal stranded wire is a stress riser and the stranded portion at the junction will fracture. There is no reason to solder terminal connections less than 10Ga in most cases. Those who do are hacks. Absolute hacks.
- Avoid the red/blue/yellow home depot/auto parts stores style terminals with vinyl insulators. These are crap. Buy proper preferably non insulated terminals and heat shrink if you need them insulated. The only reason to use red/blue/yellow insulated terminals is for paid work where time is money. If you have to use these, at least buyones with nylon insulators and use the proper crimp tool that molds the insulator around the wire for proper strain relief. It still looks like crap but will be somewhat reliable.
- Do your research into quality terminals. Buy brand name terminals. Expect them to be pricey. Most are matched to a specific manufacturers crimp tool. Expect them to be expensive. Look for names like Thomas & Betts, AMP or Molex. Expect to pay a lot. A lot being $100-$1000 depending on tool if new from the manufacturer. Ebay is your friend for secondhand crimp tools. I go as far as to stick with factory style terminals. I bought about $400 in AMP Junior power timer terminals recently for a partial harness rebuild on an 80's P-car.
- Learn about proper wire protection and sleeving. Porsche made it easy as the fabric grip tape is easy to work with. You will probably want some PVC sleeve to mimic the factory wire protection in some areas.
In short. Wiring is an artform. You can get away with a hack job but to do it well requires significant investment in knowledge, tools and components. Best avoid it if at all possible.
Also, for I think $10, you can get a 1 mo membership to hp academy. They have some good video tutorials on wiring. Here's one on splicing. https://www.hpacademy.com/previous-w...how-to-splice/ Going from memory, but I think they recommend TE Amplivar splices. The good news is that those Amplivar splices are fairly cheap and hobbyist-level crimpers for those are somewhat affordable and easily available. The bad news is that they take a bit of technique to do properly as discussed in the video.
12-02-2018, 02:48 PM
Interior Wiring Question
