Good Morning,
My '60 coupe is in winter hibernation but I start it every few weeks to keep things working. Yesterday it was warm enough to get it out and let it run and the while time the Generator light stayed on. This has never happened before, and since I have rebuilt the generator years ago I am not too concerned, it will just have to wait until it is warm enough in the garage to work on it (may be a while since it is only 10 degrees out this morning).
However, here is the question I have, more of a mystery: The generator light stayed on no matter what the engine speed. I have a long driveway so run the car up and down to exercise all the brakes, etc., and the light stayed on whether I was accelerating, stopping, idling, BUT, whenever I shifted into reverse the generator light would go out! It didn't matter if I was moving or idling, as long as in reverse there was no light. Shift into any other gear and the light would come back on.
Does anyone have a thought of why this would happen? I can't fathom a connection to reverse and the generator light myself??? This has me stumped.
John
P.S. - any thoughts on what to attack first with the generator light being on would be welcomed, too, since it might save me some troubleshooting time to get ready for spring cruising.
'60 Generator question
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mike harmon
- Posts: 126
- Joined: Sun Aug 24, 2003 2:22 am
- Location: Redlands, CA
The first and and easiest thing to do is get a good digital multimeter with multiple scales- the Actron III, model CP 7680 is a most excellent gadget. This thing is not that expensive, can be purchased at NAPA and other auto parts stores or maybe even over the internet- it even has an extremely sensitive temperature probe that can be used to measure the temperature of the tension springs of the old style electro-mechanical voltage regulators! These instruments are so accurate and sensitive they can measure electrical fields in millivolts! It's amazing how much current is wandering around even when switches are off. Using this tool I was finally able to get an exact calibration of my 62's cranky regulator in less than 5 minutes total, after warming it up. If the price of the tool puts you off a little, it can also be used with AC current, such as around the shop or the house. It's not limited to just auto work.
I can't imagine the connection between being in reverse and the generator's idiot light, but there obviously is something... maybe just bad karma? Check out your wiring diagrams to see if there is anything anywhere at all that can cross over- the dash light comes on when the battery's voltage exceeds that of the generator's output... a "backwards flow". Possibly there is a fault between the backup light switch and the wire to the idiot light, feeding the backup light's voltage to the idiot light.
Make sure the battery is fully charged, using a portable charger. Start the car with a jump from a booster battery or a booster/charger to avoid any drain on the car's battery. The first check would to check the voltage between the battery terminals with the engine running at a high (1800 rpm or more) idle after the generator/engine has reached proper operating temp., about 10-15 minutes, maybe more in your climate. DC auto generators don't have much output until that speed, particularly in the cold. The between-the-terminal voltage will be the same as the charging output of the generator, and should be between 12.5 minimum and 14.5 max. The perfect reading is 13.5, if everything is good, the battery is in good condition and the regulator's temp is within the normal operating range. The shop manual lists the output voltages for each temperature range. If the voltage isn't within that range, then you will have an indication that the generator isn't working properly, which can be due to either a malfunctioning or out-of-adjustment regulator, or the generator itself. If the voltage is proper, then the next step would be to confirm the amperage output- this isn't absolutely necessary, but is just to be sure that the generator is OK. Either connect the multimeter in series with the output wire (usually marked "gen") per instructions or buy an automotive aftermarket voltmeter and connect it into the charging wire- depending upon engine speed and battery condition, a + charging rate should show.
If everything shows that the generator is in fact charging despite what the dash light shows, then all you can do is either have the car exorcised or trace the wires from the dash light back thru the harness, using your wiring diagrams, looking for something crushing or pinching the wires, or maybe some "mickey-mouse" job of wiring repair in the past that incorrectly connected or spliced the wrong wires. Do the same thing with the wire from the backup light switch on the transmission. Hopefully whatever it is won't be too difficult to locate...
I can't imagine the connection between being in reverse and the generator's idiot light, but there obviously is something... maybe just bad karma? Check out your wiring diagrams to see if there is anything anywhere at all that can cross over- the dash light comes on when the battery's voltage exceeds that of the generator's output... a "backwards flow". Possibly there is a fault between the backup light switch and the wire to the idiot light, feeding the backup light's voltage to the idiot light.
Make sure the battery is fully charged, using a portable charger. Start the car with a jump from a booster battery or a booster/charger to avoid any drain on the car's battery. The first check would to check the voltage between the battery terminals with the engine running at a high (1800 rpm or more) idle after the generator/engine has reached proper operating temp., about 10-15 minutes, maybe more in your climate. DC auto generators don't have much output until that speed, particularly in the cold. The between-the-terminal voltage will be the same as the charging output of the generator, and should be between 12.5 minimum and 14.5 max. The perfect reading is 13.5, if everything is good, the battery is in good condition and the regulator's temp is within the normal operating range. The shop manual lists the output voltages for each temperature range. If the voltage isn't within that range, then you will have an indication that the generator isn't working properly, which can be due to either a malfunctioning or out-of-adjustment regulator, or the generator itself. If the voltage is proper, then the next step would be to confirm the amperage output- this isn't absolutely necessary, but is just to be sure that the generator is OK. Either connect the multimeter in series with the output wire (usually marked "gen") per instructions or buy an automotive aftermarket voltmeter and connect it into the charging wire- depending upon engine speed and battery condition, a + charging rate should show.
If everything shows that the generator is in fact charging despite what the dash light shows, then all you can do is either have the car exorcised or trace the wires from the dash light back thru the harness, using your wiring diagrams, looking for something crushing or pinching the wires, or maybe some "mickey-mouse" job of wiring repair in the past that incorrectly connected or spliced the wrong wires. Do the same thing with the wire from the backup light switch on the transmission. Hopefully whatever it is won't be too difficult to locate...
Mike,
Thanks so much for the detailed reply. I have not been at my computer for a week so didn't get the thank you before this.
I appreciate your response, have printed it out, and will be planning my method of attack for when the garage is warm enough to work in. The first thing I can do is get the battery charged (the charger doesn't care if it is cold, : - )
Thanks again,
John
Thanks so much for the detailed reply. I have not been at my computer for a week so didn't get the thank you before this.
I appreciate your response, have printed it out, and will be planning my method of attack for when the garage is warm enough to work in. The first thing I can do is get the battery charged (the charger doesn't care if it is cold, : - )
Thanks again,
John