Electrical connection to ammeter with alt??

[greg g]

I am studying the wiring diagram for my other project. It shows the alternator being connected to the battery terminal of tha Voltage regulator and on post and theother post is connected to the battery side of the main post of the starter solenoid. The gauge maxes at 40 amps. I will be installing a GM 3 wire alt. I was planning to wire the chaging wire to the bat side of the solenoid. As there is no external regulator, what would be a suitable place to pick up the other side of the ammeter. Since the alt put out 60+ amps, it possible the output could peg the meter, I assume this would not be a good thing, I also do not necessarily want to put the starter draw through the meter either.

Maybe I am not thinking correctly, but is the ammeter circuit a pass through of the main circuit? Guess I don't under stand how the original circuit works.

Also where can i pick up a sender for the voltage meter. That goes from switched power to ground is that correct?

And is the exciteer wire for the alt a momentary on or does it need to be continuously powered? I was thinking of powering it from the 4th post of my ford style starter solenoid, the one that hot while cranking.

[martybose]

I wouldn't worry about pegging the ammeter. I've got an 80 amp alternator on my car, and if I run it slowly (so the alternator doesn't energize) and have the headlights on, then raise the RPM a bit the gauge shows a maximum of about 30-35 amps, but just for a few seconds, then it goes down. Unless you charging into a dead short or a HUGE bank of lights, you'll normally see just a small charge.

If memory serves, my alternator is wired to the old batt terminal off of the old voltage regulator.

My voltage meter simply picks up power from the ignition switch.

The excitor wire isn't really needed. I had one installed from the coil (with a diode in the circuit) when I had my 6V alternator installed, but installed my 12V alternator without one. It doesn't charge immediately until the RPM is raised a bit, then charges continuously until the engine is shut off. It's not a big deal.

Marty

[Plymouthy Adams]

you could easily wire a second amp guage parallel to the one in the dash and keep it either under the dash or for quick reference mount it in the eingine compartment...the shunt of each will see only half the actual load..so if you are drawing 30 amps your in dash unit will reflect 15 as should the unit mounted in the engine compartment..so you you have twin 40's..you have 80 amp capacity..

[steveplym]

I've got my alt wired the same way as Marty does in my P-15 Greg. I just rev up the engine and it starts charging. I haven't tried to wire the 4th solenoid pole to it yet.

I've got my voltage meter running from ignition to ground. I trust it a bit more than the ammeter.

[BeBop138]

Greg, for my exciter wire I took a wire from the ignition switch to a small light bulb then to the alt. Turn key to on the light powers up, when you start the car the light goes off---works the same as an idiot light. I used a 42 amp alt and my gauge reads to 50 amps, that way you can`t overload the gauge and cause a fire. Another point, just recently my gauge went bad and it took out the diode in the alt. I fixed the alt and put both wires on the gauge to one post to complete the circut---turned the set up in to the idiot light system. I will convert the gauge later to a volt meter---more reliable. I thought if you use a two wire alt you have to have an exciter wire?? Good Luck.....Lee: