12v Alternator question

According to a catalog entry that I've seen for these, it is sometimes necessary to momentarily touch a wire from either P1 or P2 to the BAT terminal to excite the alternator. You're only supposed to have to do this once but given the questions that keep getting asked about the one-wires, I suspect that tractor applications are a little different from those in old cars (generally the target market). Maybe it's because tractors generally run at lower RPM's.

I don't have an answer from my own experience because I used a standard 10SI on my 2N.

You can either attach the P2 lead to the battery OR just run a short wire over to the BAT terminal on the alternator. Either will work fine considering the short lengths of wire involved.

Take a look at my website for a complete wiring diagram if you want to check your system and make sure it was done right. The link will be down below.

If you have any questions, just email me, and we'll get it worked out.

Brian

• Brian *N* S. IL's 12 volt conversion page

Most Delco 10-SI 3-terminal 12 volt conversions directly connect the BIG alternator output terminal to BOTH the battery AND the P-2 remote sense.

Its the P-1 terminal that provides excitation and can feedback voltage to the ignition coil and keep the tractor running and unable to stop it. This P-1 terminal is usually run thru an "idiot light" scheme like GM cars, like a marker light so you can excite the alternator so it will start charging and at the same time the light will allow you to turn off the tractor.

What is your P-1 connected to?..... ...Dell

And because your question was about the necessity of using a 1/2 ohm 10 watt resistor with the 12 volt frontmount ignition coil. Which it is necessary, unless you want to continually be replacing $40 12 volt frontmount ignition coils. If you do, thats ok with me, just don't come complaining about why your 12 volt ignition keeps crappin out if you don't use the 1/2 ohm 10 watt resistor.

And because I've been in the Electronics Industry for 50 yrs, I know where and how to buy resistors, and it doesn't have to be Radio Shack, but it is a source for the electrially challenged that live in the outback, but that resistor certainally won't be available at a tractor parts store eather.

BTW.....you better be certain EXACTLY what that encluded resistor is used for in you kit and use it as the instructions tell you. Most big power resistors have their electrical values printed on them like ohms and watts. It might be important for future trouble shooting, you just might want to make a note.

OBTW..... ...power resistor smoke when they get hot for the first couple of times used, and they DO GET HOT, burnie.....burnie..... .respectfully, Dell

I love when they ask why that 'thingy' is smoking...

Salmoneye

LOL. Keep the faith!

Evil Steve

FYI:

There were 2 post yesterday from the same guy (Durk, he used 2 different names, but the e-mail addr was the same) asking whether a resistor is needed with a 12 volt coil. Dell responded to each with the correct answer. Evidently, Durk took offense to Dell's tone in the responses and is taking pot shots at Dell now.

Danny

Dell gave you straight and correct info in each of his responses. Granted, each time with a little more bite.

12 volt conversion kits are not created equal! Side mount and front mount distributors makes the difference! A conversion kit for a side mount 12 volt coil does NOT need a resistor as I understand it. A conversion kit for a front mount 12 volt coil DOES need the resistor. I repeat, DOES NEED the resistor.

I hope this clears up your confusion and lighten up on Dell! He has volumns of knowledge and information that is valuable to this forum!

Respectfully,
Danny

As far as I am aware all front mount "twelve volt" coils actually run on around seven volts and need a resistor other than the ballast resistor behind the dash which you want to disconnect.

Part of the joy of twelve volt conversions is there are so many ways to do it. Some of them even work.

Your mileage may vary

Keep posting Dell. Some folks really want their questions answered.

Your mileage may vary