Alternator questions

[Andy Schuppert]

Hi all,
I have noticed that my voltmeter on my "M" only reads 12 volts. Never fluctuates at all. I"m wondering if my alternator is shot. It was previously wired wrong and troubleshot here but you guys but I"m wondering if it"s caput. I have checked my wires and they are correct. I do not have a wire on terminal 1 at all. I have one 8 gauge wire to the "batt" terminal and a jumper to 2. Any suggestions as to why I don"t show a charging voltage?
Andy

 

[Bob M]

Andy - You need a connection to the #1 terminal in order for the alternator to charge. #1 should be fed from the coil (switched) side of the ignition switch, and in series either a warning light or a diode.

Punch below for a diagram...
alternator wiring diagram

 

[Andy Schuppert]

Bob,

Thanks for the reply. I thought if I took the wire of post 1 I would have the same set up as a 1 wire alt? Oh well...

Next question to you. Do I have to an incandescent indicator or can it be an LED or some kind? I am having trouble finding a small simple panel mount incandescent indicator.

Andy

 

[Bob M]

Andy - An LED won't work since it won't draw enough current to cause the alternator regulator to "turn on". Rather you need a lamp that draws about 200 ma -or- an equivalent resistor (10 to 40 ohms, 2 watt or more).

You can also substitute a 1 amp, 100 PIV (or greater) rated diode for the lamp/resistor. If memory serves, you wire the diode so the band end is connected to the #1 terminal.

My personal preference however is for the lamp as it will provide instant indication of alternator or drive belt failure. ...Bob M