hotrodjohn71
- Jul 22, 2017
- 31
- Joined
- Jul 22, 2017
- Messages
- 31
Hi group,
Please help me with a diode question.
In a nutshell, I have a feedback problem, (12v +) from my alternator which is causing my engine to not shut off when the key is switched to off.
This is an occasional problem with some older systems with an updated relay-powered ignition and after changing from the stock 'alternator / regulator' setup to a new style internally regulated alternator.
In order to keep the srock (in dash) charge light functional after the conversion, the 'idiot light as some call it' will have its wire going to the alternator (#1 terminal) so that with the key turned on, but engine not running, positive voltage goes through that indicator bulb allowing the bulb to illuminate (because that number one terminal is grounded at engine stopped). It illustrates to show the bulb is good.
Then after the engine starts, that terminal on the alternator starts to produce positive electricity which goes back to the bulb and nullifies the bulbs lighting to show that there is charge from the alternator.
It is a commonly reported practice to install a diode at the alternator right where that number one terminal wire comes out which is supposed to allow electricity to flow into the alternator from the key switch (making the charge light functional), but not for electricity to flow from the alternator back into the key switch (which can sometimes cause an engine to not shut off with the key switch).
This charge light circuit has virtually no current going through it except for the current to turn on that little 194 bulb. I have read that some say the bulb has enough resistance to eliminate the engine run on problem, but in my case, not so..
I have found that there are about four different styles of diodes which the guys use but I would wonder which would be the best or if it makes any difference at all.
I've seen 1A 100V, 6A 50V, 1A 200V, 1A 50V.
Would these work? Or would there be a better? Thank you
Please help me with a diode question.
In a nutshell, I have a feedback problem, (12v +) from my alternator which is causing my engine to not shut off when the key is switched to off.
This is an occasional problem with some older systems with an updated relay-powered ignition and after changing from the stock 'alternator / regulator' setup to a new style internally regulated alternator.
In order to keep the srock (in dash) charge light functional after the conversion, the 'idiot light as some call it' will have its wire going to the alternator (#1 terminal) so that with the key turned on, but engine not running, positive voltage goes through that indicator bulb allowing the bulb to illuminate (because that number one terminal is grounded at engine stopped). It illustrates to show the bulb is good.
Then after the engine starts, that terminal on the alternator starts to produce positive electricity which goes back to the bulb and nullifies the bulbs lighting to show that there is charge from the alternator.
It is a commonly reported practice to install a diode at the alternator right where that number one terminal wire comes out which is supposed to allow electricity to flow into the alternator from the key switch (making the charge light functional), but not for electricity to flow from the alternator back into the key switch (which can sometimes cause an engine to not shut off with the key switch).
This charge light circuit has virtually no current going through it except for the current to turn on that little 194 bulb. I have read that some say the bulb has enough resistance to eliminate the engine run on problem, but in my case, not so..
I have found that there are about four different styles of diodes which the guys use but I would wonder which would be the best or if it makes any difference at all.
I've seen 1A 100V, 6A 50V, 1A 200V, 1A 50V.
Would these work? Or would there be a better? Thank you
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