Passat: current capacity of rear 12V power outlets?

I use 14 gauge wire for most automotive applications. That size is not only capable of handling most current requirements, but is also heavy enough to resist breakage in the tough automotive environment. That is what I used when I added a 110 volt power outlet to my car.

If in doubt, though, try 12 gauge. However, the wire will be much stiffer and take longer to solder.

By the way, house wiring is mostly 12 and 14 gauge.

HTH

snipped-for-privacy@my.fun (Papa) wrote in news:cWfeh.8041$ snipped-for-privacy@newsread4.news.pas.earthlink.net:

Very interesting, but not what I'm asking; I'd like to know the gauge of the wire that's already being used in the run to the rear power outlets.

For loads of 10A at the distance from the battery to the cargo area, wire of at least AWG 12 should be used, with AWG 10 being preferred.

I don't know the answer to what you asked.

That is not true. OK. It may be true if you mean that is what *you* prefer. Don't expect an automobile maker to meet your preferences. AWG 18 is sufficient for 10 amps in a car from a safety point of view. Yes, bigger gives less drop, but you still don't *need* 12 GA for 10 amps in a car usually.

Looks like you'll have to ask VW. Details such as that are rarely known at the dealership. What are you planning to plug into that outlet anyway?

10 gauge wire? Wow!!

snipped-for-privacy@my.fun (Papa) wrote in news:tJgeh.8054$ snipped-for-privacy@newsread4.news.pas.earthlink.net:

I'd hoped to get an answer by asking here; people who participate in this newsgroup know lots of things.

I suggest that you try the VWvortex forums. Many experts participate there. I'm sure someone will have the answer you seek.

">> I'd hoped to get an answer by asking here; people who participate in

Our Eurovan Camper has the 12V 'convenience' outlets on a breaker (separate marine-type deep-cycle battery) at 10A. The Volvo also has them fused at 10A. They are listed on the fuse block as 'power point'.

Cigarette Lighters are *VERY* special applications, usually fused at

30A, and NOT typical of a standard power-point. Don't assume that since your lighter can take all sorts of current, so can a power-point. They cannot.

Keep in mind that automotive wiring (and applicable calculations) are based on DC current, not AC, and assuming a nearly infinite-amperage source (A lead-acid automotive battery will essentially melt itself down and deliver more than 500A (for a very few seconds) if given the chance). So calculating wire gauge is not anything at all like calculating household wiring.

Distance is a factor. Current is a factor. And the nature of the wire is a factor. Automotive wire *MUST* be stranded, must be able to withstand extremes of heat and cold (and remain flexible) and so forth. What you get at an electrical supply house except as it may be labeled "Approved for Automotive Use" is NOT suitable. Period. Even very tough wire such as "stranded" THHN/THWN commercial-grade PTFE-coated wire is NOT annealed, and the insulation does get brittle under extremely cold conditions. DO NOT even try to use this stuff unless you enjoy nasty shorts and potential fires. That battery WILL drain down if given a chance, and 9.5A @ 12.6V (just below the failure point of the fuse) =

119.7 watts of heat... draw your own conclusions.

So, were I to advise anyone wishing to install additional power-points, I would suggest the following:

1. Purchase ONLY wire rated and approved for automotive use.
2. Stick with high gauges, 10 or 12, unless the runs are very short and/or for specific accessories of known current draw.
3. Double-insulate everything, sleeve at any penetrations, leave slack (!!!) on both sides of any tie or hard point, and protect everything when done.
4. Fuse at no more than 10A. If your Boom Box Stereo needs more than

10A, run a dedicated line to it with the proper in-line fuse and the proper additional protection.

1. And (yeah, I have seen it, really) NEVER, NEVER fuse the ground side. EVER.

Peter Wieck Wyncote, PA

Have a look here:

of vw circuit diagrams, wire gauge is in mm2 SFC

"Bert Hyman" schreef in bericht news:Xns989361D6919EBVeebleFetzer@127.0.0.1...

I don't have info on the Passat, however the Bentley manual shows 2.5 mm wire fused at 30 amps for the trunk mounted convenience socket in the 2002 Golf and Jetta.

Makes sense as 10 gauge wire is just over 2.5mm. And 12 gauge is just over 2mm.

Peter Wieck Wyncote, PA

Thanks! That's somewhere between AWG 12 and 10 and probably enough for my needs.

With that, it's now probably worth pulling off some panels and looking at what's really there and how it's all put together.

I would imagine that the actual reason they use mm^2 rather than AWG is that AWG stands for *American* Wire Gauge; European countries don't use it.

-- Mike Smith

Standards are great; everybody should have one of their own.