Quick question. I was wondering what gauge wiring is most common throughout a build. I know 12ga for ignition (30), but have heard mixed messages on the rest; either 14ga or 16ga wire. Any thoughts?
Jeff
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Headlights & grounds: 14 Signal: 16 Park Lts: 16 Horn: 16 Wiper:16
Gauges: 18 Tail Lts: 16 Brake Lts: 16 Ignition / coil: 16 Tach:16
Oil temp & Pressure: 16 Starter solenoid: 14 "Batt" Ignition switch to 30 Starter: 12 Starter 30 to Alt B+: 12
Thanks Alan!
I know Alan has a TON of experience here, so I don't want to disagree with him.
I use thicker wire in a couple spots.
I use 12 or 10 gauge to the starter solenoid, not 14. The starter is only used for a few seconds, but you want ALL the voltage getting to the solenoid to engage the Bendix quickly.
From the starter to the alternator I use 8 gauge minimum. 12 gauge is good to 20 amps, 8 gauge is good to 50 amps. The typical alternator of 55 amps will put out a steady 30 amps or so, 55 is only a momentary peak output. But again, you want ALL the voltage from the alternator to reach the battery via the starter and main battery cable.
What you don't want is voltage to drop a half volt or even toward a whole volt in travel through the wiring. Too small wiring can do that.
On the other side of things, grounding is just as important. I use 3 ground cables on my cars. One from the bellhousing/engine mount to the frame, second from the nosecone mount to the frame, and third from the battery directly to the steel frame. The heavy battery ground goes directly to the transmission.
Clean, bare metal is important, as is the use of star washers between cable ends and the clean metal chassis/engine. This is important, and bad ground connections are the cause of many problems.
Much appreciated!
IF your battery is in the frunk and the kill switch or starter is in the back etc etc on my car the wire is a TWO gauge I believe. Just saying.
If anyone is looking for 00, #2 or #4 battery cable for their projects, for a little more money you can buy that gauge in welding cable from a welding supplier near you. They also have it in red and black covers.
The advantage of that cable is that it has many more and finer wires and they are much more flexible to maneuver the cable around in the car from front to back, if needed. They may have the ability to crimp the appropriate lug connector on either end, once you get it cut to the proper length, too.
Some truck fleet electrical/parts suppliers can supply all this stuff, too.
Good Idea Gordon.
@Gordon Nichols posted:If anyone is looking for 00, #2 or #4 battery cable for their projects, for a little more money you can buy that gauge in welding cable from a welding supplier near you. They also have it in red and black covers.
The advantage of that cable is that it has many more and finer wires and they are much more flexible to maneuver the cable around in the car from front to back, if needed. They may have the ability to crimp the appropriate lug connector on either end, once you get it cut to the proper length, too.Some truck fleet electrical/parts suppliers can supply all this stuff, too.
That’s what I used when I relocated my battery to the frunk. 30’ of 00 was ~$50 and I ran it down the driver’s side tube (Spyder) and out just aft of the shock mount.
Carey warned me that the tube is full of self tapping screws so I wrapped the part in the tube in split wrap.
I thought it was going to be a royal PITA but it turned out to be a breeze. Ran fish tape forward and it slid right through without catching a single screw.
Another thing I learned on that project is that nut splitters make dandy battery cable end crimpers.
@dlearl476 posted:Another thing I learned on that project is that nut splitters make dandy battery cable end crimpers.
What a great tip.
Nice. Inside the frame tube is how Porsche did it.
@Stan Galat posted:What a great tip.
It didn’t quite give me the amount of squish I wanted, so I ground about an inch off the end and ground the sharp edge so it didn’t split the connector. Put it in the vice and used an impact driver on it.
$5 at Harbor Freight I figured I could sacrifice it for a good crimp.
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