Charging Light wont go off!

[brucejohn]

It sounds like the wiring in the ignition switch is quite right.

My fingers got behind my mind, I meant to say ...ignition switch wiring ISN'T quite right.

It could be the switch, though more likely the wiring. Does the light go off when she is running?

[cetesse]

The light does go off when she is running. Note, with key removed and ignition off. The battery does drain all the way out pretty quickly.

[brucejohn]

I am back to origial suggestion, wiring diagram and multimeter check all the important parts.

Are the existing wires the right colors? Or has someone rewired it in the past?

[cetesse]

Majority of the wiring is original. A few changes but largely reflects circuit diagram.

looks like i will spend some time investigating more.

Thank you.

[greasyhandsagain]

Wow Id want to be checking that thing out ASAP. Since youre losing juice, somewhere you have a short circuit...or some type of bad current draw. You're risking cooked wiring...or maybe even an electrical fire.

Maybe Im paranoid...but Ive had this happen before, some years ago, and that charge light was on much the same as what youre describing. It was a voltage regulator problem, only solved by a new unit.

[Terrys]

The Ign. warning light (charge indicator) gets 12 volts applied when the key is turned on. It's current path is from + from the keyed switch, through the lamp, and to geround, through the solid state regulator in the alternator. When the truck is running, the output of the alternator rises, so that as the voltage approaches that of the keyed battery voltage, the lamp has less voltage across it, until voltage from the alternator is equal to that of the keyed circuit. If the lamp stays lit, after the key is turned off, then it is getting it's current path through a faulty regulator pack, and find it's way to ground through any number of the other circuits also on the now 'cold' side of the switch. If it were only one circuit, the lamp would only glow dimly, but as there are several circuits, the total resistance is less (the resistance of two parallel circuits is less than each one individually) the lamp will glow brighter. If the lamp is staying illuminated when ALL wires are removed from the alternator, clearly, somone has been into the harness with mods, as it would otherwise be completely open ended.
The average auto parts store checks an alternator for output, but simply seeing a voltage output when it's spun doesn't confirm that the regulator pack is operating as it should. Many situations where the battery goes dead can be a direct result of a bad regulator pack. One (or more) of it's diodes is allowing current to go in either direction (alternator windings to battery when running, battery to windings when not running. This is quickly and easily verified by simply feeling that the alternator is warm, long after shutdown.

[cetesse]

Hi All,

Thanks for the many help and suggestions. Found the culprit today.

For some reason, the main RED wire from the battery to the Delco alternator had been stripped in a 2 inch section. A wire from the temp sending unit, the brown-yellow wire to the charging light and the wire to the temp gauge were all tied around this main Red line.

I've removed them and moved things back to factory spec. Brown yellow to alternator. Temp send connected to wire to temp send gauge. Repaired the red wire.

No I need a flash unit and I think I've got everything back in place.

[Nium]

Makes ya wonder what the PO was thinking when it was decided things like that were a good idea.

[greasyhandsagain]

yeah thats just plan crazy. something so wacky like that...when you find it...and it all works right again. Thats a good thing. Really makes a 'normal troubleshooting' effort difficult though.

[SafeAirOne]

Hi All,

Found the culprit today.
For some reason, the main RED wire from the battery to the Delco alternator had been stripped in a 2 inch section. A wire from the temp sending unit, the brown-yellow wire to the charging light and the wire to the temp gauge were all tied around this main Red line.

Interesting. I don't think there is a LESS APPROPRIATE wire to draw 12v from on the whole truck!

Good job finding the problem. The symptoms just didn't make sense for an unmolested wire bundle.

BTW--Nice work finding the hack job. If your SIII instrument panel is anything like mine, its a mass of spaghetti back there with about 2" of clearance to work/trace wires.

[cetesse]

Yeah, I know, I actually took the entire lower dash off to get more room. Am going to clean things up a bit and confirm that is the only short draw going on.

I did find my light switch has 3 settings, Off, just small white lights, full lights - probably the exMOD nature.

All for now

[SafeAirOne]

I did find my light switch has 3 settings, Off, just small white lights, full lights - probably the exMOD nature.

I think they all have 3 positions--OFF, PARKING LIGHTS, HEADLIGHTS+PARKING LIGHTS.

[brucejohn]

I think they all have 3 positions--OFF, PARKING LIGHTS, HEADLIGHTS+PARKING LIGHTS.

Yep, mine too. Separate switch for instrument panel lights.

[kevkon]

While you have the dash apart it would be a good idea to remove the tape wrapping the harness and inspect all of the wires. I had a PO patch which I corrected easily enough. Problem is when you see one of those bad splice jobs it usually was done for a reason. In my case the PO had a fried wire in the harness which he replaced with a new line outside of the harness. However, when I removed the harness tape I found that the original wire had melted onto other wires which now had damaged insulation. It pays to inspect all of the wiring on these old vehicles. Another thing I did was replaced that tape with convoluted tubing. It protects the wiring, organizes it, and as a benefit you can add additional wiring pretty easily.