Quote:
Originally Posted by TrickyT
The downside of this approach is that the 10AWG wire circuit is now protected against shorts by a 150A fuse instead of the "Main 2.0L" fusible link. I've never seen an equivalency table that goes from fusible link cross section area to amperage capacity, so I'm not sure how much of a problem this really is. Normally a 10AWG wire would get fused with a 30A fuse. But the 2.0L fusible link must be of greater capacity than this, since it was designed to handle to the full 80A output of the OEM alternator. Still, if a short occurs you want the 150A fuse to blow and not for the #10 wire to turn red hot and start a fire.
Note that all of the various circuits that the #10 wire feeds have their own fuses, so the only thing that is of concern here is what would happen if the 10AWG white wire shorts to ground because of an accident or because its insulation gets compromised. Perhaps an experiment is in order; connect a 4ft length of 10AWG wire through a 150A fuse to the terminals of a 12v car battery and see what happens. If the fuse blows then I think Bill's suggestion is a viable approach. If the wire turns red hot and the insulation melts then it's not such a good idea. If someone tries this out, please post the results.
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I’m not sure about that downside. I would ask this question. Does the cruiser run with the battery disconnected? If yes, either the Main 2.0L fusible link or a 150 amp fuse would only protect the small white wire from the battery, not the alternator. In the accident or wire short scenario if the motor was still running it would not matter if either fuse failed as the small white wire would still get output from the alternator. Maybe unregulated.
TrickyT’s point is well taken. Any alterations we make can have consequences. If this is not acceptable, leave it stock. If concerned about TrickT’s point with the above wiring option, fuse the small white wire at the alternator.
Before we pull our hotdogs out for the wire test I need to make a couple corrections.
I said the small white wire was “about” 10 gauge; it’s actually closer to 7 gauge. The 10 gauge wire is 12 inches away from the “B” alternator terminal. Second the fuse link wire measures around 12 gauge not 14 gauge. I measured the copper now instead of “abouting”, first with an American standard wire gauge and then with a micrometer. They still will not be exact but closer to correct.
The diameters of the wires are as follows:
Main charging larger white wire was .160 inches……..~ 6 gauge
Smaller white wire .140 inches……..~7 gauge
Blue fusible link wire .082 inches…….~12 gauge
12 inches from the “B” post on the alternator the .140 inch smaller white wire has 2 wires bugged on. The diameter of each wire is .100 inches…….~10 gauge One of these wires goes to the under hood 15 amp EFI, the other to the headlight relay.
The .140 inch white wire continues through the firewall to the in dash fuse panel. At least 3 other wires are bugged off this to feed circuits in the fuse panel. 10 amp ECU B, 15 amp OBD, 20 amp defog, and 40 amp FL heater. I did not measure these wire sizes nor look where the splices were. To sum up, an ~7 gauge wire runs from the alternator “B” post in to the in dash fuse panel with at least 5 wires bugged off of it some of them ~10 gauge.
Bill
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