Alternator Not Charging Battery

[Maxie Allen]

I have installed a Delco Remy 12v alternator and was wondering if it is working correctly about how many amps should my ammeter be showing while running? Also does the #2 wire (P2) have to be connected to the bat+ at the back of the alternator or directly to the battery post. Thanks for any information.

 

[old]

#2 from the plug can go either to the big post on the alternator or to the same place you hook the wire from the big post. But to save $$ its just as easy to hook it to the big post on the alternator so as to save wire. As far as how many amps depends on how charged or discharged the battery is and how good or bad it is

 

[Tom N MS]

Maybe this will help . http://www.ytmag.com/nboard/messages/600572.html

With engine runningat about 1/2 throttle check across the battery post with an analog meter. Digital ones go crazy on these old tractors and other old stuff. Your meter should read about 12-14.5 volts if the alternator is working right.

 

[ZANE]

Yes it does have to be energized. Connecting a jumber to the big hot post of the alternator permanently will work if you disconnect the battery cable every time you leave the tractor as much as overnight. It will cause a drain on the battery otherwise and you will find a dead battery next time you go to start it.

That is where the diode in a wire to the p2 terminal from the battery supply comes in. A diode will allow juice to go into the alternator fields to excite them but when the engine is shut down and the power taken from the diode from the battery the alternator can't push the current back into the ignition battery circuit and keep the ignition energized.

There is another way to energize the Alternator. It doesn't matter what brand of alternator it is either and does not involve a jumper, diode or marker light. It is to use a two wire voltage regulator from a mid 50s Chrysler product that had an alternator. Juat run a wire from the ignition switch to one of the two terminals that is marked IGN and the other wire to the p2 terminal of the alternator. I have had one rigged that way on my old IH backhoe that came with a Prestolite generator for over 25 years and it works perfectly still. The alternator I put on the IH is a Motorolla.

Zane

 

[souNdguy]

#2 post to the big charge stud. Your tractor only has a few feet of wire.. and it's pretty good gauge... not much votlage loss.. a car has hundreds of feet of wire.. so the #2 wire is run tot he battery hot terminal so the alt can sense the votlage drop at the battery and adjust charge voltage up...

Your #1 wire needs to be run thru an idiot lamp or diode to the same side of your ignition switch as your coil is hooked to.

On a real well charged healthy battery, right after start you will see high charge for a few minutes that will taper down to near 0 after a bit...



soundguy