Winch-Triggered Alternator
IF THE IMAGE IS TOO SMALL, click it.
I HAVEN'T FULLY TESTED THIS YET, so even though I think it'll work, I can't recommend anyone does it.
I don't recommend this mod for any 2G alternator because of their known weak B connection. 4G & most later alternators don't have an exposed Field screw or terminal because of their internal voltage regulators. On a 2G or 3G, the FIELD screw is the one marked "GROUND HERE TO TEST".
The idea of this mod is: when the winch is pulling (doing work), the alternator should be at its max output to keep the voltage up, and to prevent the battery from discharging. When the winch is spooling out (no work), there's no need. So the full-field relay is only activated by the IN button.
This mod isn't suited to portable winches or those controlled by a pendant because there's no good place to attach the relay's trigger wire without disassembling the winch and adding a connector. Further: the alternator's mounting bosses & output wire must be clean & solidly-attached before attempting to full-field it under load.
Since this mod uses the dash-mounted winch switch, the operator should monitor the voltmeter during use. If voltage exceeds 16 for more than a few seconds, disable the relay and use the winch as usual. But if the winch is large enough to need this mod, voltage should fall slowly, even with a super-high-output alternator.
Also, alternator temperature should be checked frequently if the winch is used more than a few seconds under full load. If it approaches 230°F, disable the relay.
A typical winch control needs less than 5A, so a 5A fuse should work in most applications between the ig.sw. and the winch dash switch.
