One wire alts use marine regulators and it's called flashing the field. If it's not a si series you can flash the field by touching the stator wire with a curcuit light. That way if you accidentally touch the case the light will light up instead of arching.
I've had good luck just buying an 80's alternator and installing an idiot light to excite it when the key is turned on. (old tractors). Cheaper than buying the "one-wire" jobs. On one tractor, I wired the excitation wire through a 20 ohm resistor to the light switch, so I could just pull the light switch to start it charging if it sat for too long and the self-excitation didn't kick in (this one was a 'one-wire' alternator job).
what I have had to do on the non self exciting alternator is to put a timed relay on the start side so it has 12 volts when the alternator is running for 5 seconds which get the alternators going, wont charge just via key as when engine starts the alternator once running then needs to be excited, the exciting thing was I had a hellovagood time on my project.
What about 24 volt alternators? Same concept …take the hot coming off 24 volt battery cable/post and hit the "R" terminal on an SI alternator to get it excited? Thanks for the good video and instruction here.
I have a GM10si alternator with internal regulator. I'm rewiring my pickup truck and have no wiring harness and new wires being installed. I have the positive post wires to the battery. My question is. T1 post to the positive post constantly or just momentary to excite it. Would it fry the wire if it is on constantly? And does the t2 post need to be connected?
I have a new SI series alternator which I put on an old diesel tractor. I thought it was a 1 wire alternator but after i initially excite the fields and then shut it down, on re-start it doesn't seem like it has any residual magnetism (it no longer charges). Should I install a jumper wire from #2 to the + terminal, and also an "idiot light" in between #1 and the key switch? Thanks.
That is exactly how you hook up the 3-wire units, only you technically don't need the jumper from the + post to the #2 terminal. There can be a problem with this, though, as voltage can backfeed up the key-switch and keep your engine running even when the switch is off (you have to pull the battery wire to shut the engine off). Including a diode between the switch and the #1 terminal fixes this, it's called ignition anti-feedback diode.
You should still need it on a diesel. Instead of keeping the ignition active, the back-feed will keep the solenoid that opens either the injection pump or the air valves active.
no, but continuouly connecting the tach to positive will put about an extra 50 ohm load on a connected battery even when the alternator is off; not much unless the battery is weak, small capacity ,or stays connected for an extended period of time
Rýán Túçk Exactly right. There's also a problem with that AC signal from the stator (which the tach line is a direct connection to) leaking to the batteries.
One wire alts use marine regulators and it's called flashing the field. If it's not a si series you can flash the field by touching the stator wire with a curcuit light. That way if you accidentally touch the case the light will light up instead of arching.
I've had good luck just buying an 80's alternator and installing an idiot light to excite it when the key is turned on. (old tractors). Cheaper than buying the "one-wire" jobs. On one tractor, I wired the excitation wire through a 20 ohm resistor to the light switch, so I could just pull the light switch to start it charging if it sat for too long and the self-excitation didn't kick in (this one was a 'one-wire' alternator job).
what I have had to do on the non self exciting alternator is to put a timed relay on the start side so it has 12 volts when the alternator is running for 5 seconds which get the alternators going, wont charge just via key as when engine starts the alternator once running then needs to be excited, the exciting thing was I had a hellovagood time on my project.
Going to try this. Will let you know if it works!🙏🙏🙏🙏🙏
What about 24 volt alternators? Same concept …take the hot coming off 24 volt battery cable/post and hit the "R" terminal on an SI alternator to get it excited? Thanks for the good video and instruction here.
I have a GM10si alternator with internal regulator. I'm rewiring my pickup truck and have no wiring harness and new wires being installed. I have the positive post wires to the battery. My question is. T1 post to the positive post constantly or just momentary to excite it. Would it fry the wire if it is on constantly? And does the t2 post need to be connected?
very interesting
How wood I excite my 99 ford explorer alternator 3G
I have a new SI series alternator which I put on an old diesel tractor. I thought it was a 1 wire alternator but after i initially excite the fields and then shut it down, on re-start it doesn't seem like it has any residual magnetism (it no longer charges). Should I install a jumper wire from #2 to the + terminal, and also an "idiot light" in between #1 and the key switch? Thanks.
That is exactly how you hook up the 3-wire units, only you technically don't need the jumper from the + post to the #2 terminal. There can be a problem with this, though, as voltage can backfeed up the key-switch and keep your engine running even when the switch is off (you have to pull the battery wire to shut the engine off). Including a diode between the switch and the #1 terminal fixes this, it's called ignition anti-feedback diode.
alternatorman But I don't need the ignition anti-feedback diode because the tractor is diesel.. no ignition system on board... correct?
You should still need it on a diesel. Instead of keeping the ignition active, the back-feed will keep the solenoid that opens either the injection pump or the air valves active.
How to excite the 1 wire alternator???? I tell it that we are going to Disneyland-MAN! does it get excited!!!!!
can you leave a live 12 volt wire connected to it too excite every time or will it ruin it if it is not spinning
no, but continuouly connecting the tach to positive will put about an extra 50 ohm load on a connected battery even when the alternator is off; not much unless the battery is weak, small capacity ,or stays connected for an extended period of time
Rýán Túçk Exactly right. There's also a problem with that AC signal from the stator (which the tach line is a direct connection to) leaking to the batteries.