Red Charge Light

[Andrew IIA]

Hi Group,

My charging system stopped charging over the past weekend. I suspect the red charge light unit on the dash, but tell me what you think.

Battery is functioning reasonably well. Alternator (Delco 10si, 1 wire, new two months ago) seems to be okay. Red charge light is now never lit: not on key-on (before starting) or any other time.

Am I correct in thinking that if the light itself has failed/died that my working alternator and battery will no longer be connected to one another :confused: How should I proceed ?

Thanks, Andrew
'63 SIIA 88" SW

[SafeAirOne]

Well, I can tell you that if the tiny wire (brown w/ yellow tracer) that goes from the alternator to the charge light on my SIII is disconnected or broken, the charge light won't EVER light and the alternator won't put out electricity either.

Presumably you've done away with your external voltage regulator, so check the yellow wire and associated circuit/bulb for an open circuit.

[Andrew IIA]

Thanks Mark,

I will investigate that connection today and report back :thumb-up:

Best regards, Andrew

[TeriAnn]

Battery is functioning reasonably well. Alternator (Delco 10si, 1 wire, new two months ago) seems to be okay. Red charge light is now never lit: not on key-on (before starting) or any other time.


The circuit should be: switched 12V to red light then red light to pin #1 on the 10-si's molex connector. The wire should be AWG 14 but you can get away with AWG 16 on a 10-si alternator.

This wire provides the start up voltage for the alternator and is used to supply the magnetic field inside the alternator with the voltage needed to operate.

So obviously if your red light never comes on in the key on, engine off condition you do not have 12V needed to create the magnetic field necessary for the alternator to function. You have already found your problem. You have an open circuit. A dead bulb or more likely a bad connection.

[Andrew IIA]

With your excellent advise Mark and TeriAnn I have determined that there is switched 12v power to the red-light socket from the ignition, and that the bulb is functional.

I haven't located any obvious breaks of faults in the wire connecting the light socket to the alternator. So I think my next step will be to connect a new temporary wire to make that connection and see if it then works properly.

Wish me luck ! Andrew

[SafeAirOne]

Usually, mine looks connected at the alternator, but the wire is really broken inside the blade connector (I have a really lousy crimper).

[Andrew IIA]

Okay. I ran a brand new 14 gauge wire from the lamp socket to the # 1 post on the alternator and ... nothing, no change. But if I allow the new wire to come into contact with the metal housing on the alternator the red light comes on (complete circuit achieved). The red light will light whenever I touch it to a decent ground point (and the ignition is 'on' of course). But when I attach it securely with a well-crimped connector to the appropriate alternator blade - nothing.

So, is the internal wiring of my Delco alternator (re-man'd, 2 months old) cooked ? :(

Frustrated here, Andrew

[graniterover]

Wouldn't be the first time for one of those. I'm guessing you got a warranty with it though? The one currently on my truck has been on two vehicles and the first was a plow truck (snow, sand, salt, etc.)

Does sound like you've found the problem.

Mark

[SafeAirOne]

You wouldn't believe how many bad "rebuilt" alternators are on the shelves of auto parts stores all across America right now. My current alternator is a warranty replacement--the one it replaced, like yours, lasted only a week or two before the internal voltage regulator went bad.

[Andrew IIA]

Thanks for the advice everyone. The Delco alternator is warranted, so I will pull it and take it back to NAPA forthwith. Hopefully that will clear up my issue. I will report back.

Always learning, Andrew

[Andrew IIA]

Replacing the Delco alternator fixed her right up ! Thanks everyone for your help; I learned a lot:thumb-up:

[SafeAirOne]

Replacing the Delco alternator fixed her right up ! Thanks everyone for your help; I learned a lot:thumb-up:

Glad the problem is fixed. I've come to expect a junk alternator from an auto parts store about 50% of the time, unfortunately.