Charging Light wont go off!

[cetesse]

Hi,

I have Series III 109" with the 2.25L petrol engine -- early 80's exMOD Civilian model.

The charging light stays on ever when the ignition is in the off position and the key is removed. Also the brake lights nor the turn signals work when the vehicle is on.

How do I go about troubleshooting this?

Thank you in advance.

Chris

[brucejohn]

It sounds like the wiring in the ignition switch is quite right. Do the lights work when the ignition is off?

Our hosts have the electrical diagram with color codes and all available on the electrical page. Download, print, grab your multimeter and start chasing down.

Let us know what you find.

[greasyhandsagain]

have the points in the regulator stuck together?


If this is something that just happened right now Id not want to be leaving the battery connected..........

[SafeAirOne]

I had this happen (twice) on my SIII w/ 2.5 NA diesel. Turn off ignition, remove keys, charge light stays on.

My Alternator (or its built-in voltage regulator) went bad. I replaced the alternator with the NAPA equivalent, but the charge light was still on. I took the new alternator to an automotive electric place who tested it and found that the alternator was bad. Got another one from NAPA which has been working fine for the last 4 years.

[brucejohn]

Hey, that all is well and good, but unless my memory is bad the warning light is in the ignition switch circuit. Wired correctly the warning light cannot be on when ignition is off.

[cetesse]

Hi all,

Thanks for the replies. The lights do work most of the time when the ignition is off.

If I leave the battery connected it does pull the battery all the way down. The truck sat for 3 years before I got her. So far I've replaced:
1) the battery
2) the starter,
3) starter solenoid
4) and pulled the alternator (and had it tested by the auto shop - it tested good). Its a Delco aftermarket.

She is starting now, and running decent. Still work to do.

How would I test to see if the points in the regulator stuck together?

Thank you,
Chris

[SafeAirOne]

Looking at the wiring diagram (click) (http://www.roversnorth.com/store/images/category/medium/LR-page84.pdf) the only thing the brake lights (49, 50) and turn signals (18, 19, 20, 21) have in common is that they both get their power from terminal 2 on the ignition switch (23). If the switch wasn't putting out power at terminal 2, the engine wouldn't run (no power to coil (33)).

I think that eliminates almost everything except a bad alternator. You might take it down and have it tested at your local auto parts store.

EDIT: I believe that your alternator (like all series III and modern aftermarket alternators) has a built-in voltage regulatro which, if I'm not mistaken, is solid state and unlike the mechanical regulators on the older series trucks, have no points that open and close regulating voltage. I could be wrong, though--I don't have a 2.25 2/alternator installed in my SIII. Despite your having the alternator tested, I still believe that is the culprit.

[cetesse]

Just a note -- if I disconnect all wires from the alternator - the light stays on.

If I disconnect ground and/or feed from the ignition coil (also just replaced) - the light goes out.

EDIT ... I also modified the stock circuit diagram by adding color to the leads -- might be a bit lazy but found it helpful in troubleshooting. Enjoy the doc.
http://docs.google.com/fileview?id=0B0k4Jw6f3dBpMTBhMmVhNGQtZDFmOC00NDM2L WIyMTQtZjQ2OGFjODEzMGM3&hl=en
(you'll need to download it to view in full color, Google makes it look like a black page)

[SafeAirOne]

Just a note -- if I disconnect all wires from the alternator - the light stays on.

If I disconnect ground and/or feed from the ignition coil (also just replaced) - the light goes out.

What are your temp and fuel gauges indicating while all this is going on?

[cetesse]

The temp gauge moves all the way to top (HOT) when ignition is off. Performs normally when ignition on and engine running.

The fuel gauge is not operable right now.

[brucejohn]

That's right same post as alternator warn light. Ignition switch post 2 is switched on and off with the key, right? If it was wired correctly brake lights and alternator warn light could not be on when ignition is switched off.

Or am I missing something?

[cetesse]

Could it be the ignition switch itself?

[SafeAirOne]

The temp gauge moves all the way to top (HOT) when ignition is off. Performs normally when ignition on and engine running.

The fuel gauge is not operable right now.

Hmm...When the truck is off, the temp gauge should read full cold. Do the turn signals and brake lights work with the ignition in the "OFF" position? I'm wondering if terminal 2 on the ignition switch is always hot with the key in the off position. It should only be hot in the on and start positions.

BTW, are you sure the switch is all the way in the "OFF" position when you removed the key? My "key" can be any thin, pointy object and can easily be romoved with the switch in any position. In fact on washboard roads, my keys fall out all the time.

EDIT: I've also had to change my ignition switch as it refused to energize terminal 2 in the "run" position.

[SafeAirOne]

It sounds like the wiring in the ignition switch is quite right. Do the lights work when the ignition is off?

Ahh... I think brucejohn and I are arriving at the same conclusion, except he is way ahead of me. I'm going to presume the above quote is a typo and that you meant to say "It sounds like the wiring in the ignition switch is NOT quite right."

In that case, I'm beginning to agree. :)

[cetesse]

Pretty sure the key is all the way off. Straight up & down and the cylinder pops out flush with the casing.

The turn signals aren't currently working but I think that's the flasher unit - trying to get the charging light fixed first. The emergency brake light only comes on (briefly) when the ignition first starts up. The brake lights aren't working, but like the turn signals they did briefly work when the truck arrived a month ago.

How hard was it to change out the ignition switch? I imagine just not a lot of room to work?

[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.