Gerald K4NHN wrote:
Here is a diagram from a service manual for the alternator on an 82 Luv, it should be about the same..One is the 12 volts to excite the alternator, one is the output and the other one is for the charge relay. The IG and S may be stamped on the housing some where, but I've never looked at one in hand. It looks to have the regulator built inside the housing. Hope this helps. With an ohm meter that has a diode position on it, you should be able to ohm out the terminals and tell which is which.
Brilliant, thanks muchly!
According to that diagram, L, S, and IG appear to be the designations for this mystery connector's wires. After looking at it a few times, I'm not sure how this circuit works.
Only thing I'm really sure of is that L controls the "Charge Relay" and it doesn't do anything but turn the dash light on and off. It's normally open, so this means that energizing it turns the light on, and lack of juice turns the light off. It appears to cheat and use a satuartion principle to do this. It must be a very precise relay, probably gets finicky when it gets old, or connections get a tad crunchy... very likely to give a "false positive" for telling you the alternator isn't charging, when it actually is.
IG appears to apply power to the Regulator. S confuses me, as it appears to be a perpetual dead-short through D12... Then, uh.... R3 and R2 slowly drain the battery until it is dead, any time the engine is not running.... ,:-/ I hope R3 and R2 are REALLY big.... F is internal? L is the wire I'm going to ignore and leave unconnected, since it really doesn't do anything but provide human data via the dash light.
Since IG is intended only to be energized when the key is on, I need to be able to tell the difference between the two inputs needing 12V.
As you say, Gerald, I should be able to figure it out with the MM. I suppose I'll tie IG to the Fuel Cut-off Solenoid, as soon as I figure out which one that is...
No, just for good measure... That S connection bugs me, being a completed circuit from +12V to Ground at all times, key in or not. I'll put them both on the switch. It might be a guarantee against capacitance.... But I'll try it my way first.