So I've been troubleshooting a problem with my 1979 Warrior II. The ALT light is on and nothing at the amp meter. I see the battery is at 12.2 volts. I have fully charged the battery.
So I have a new Alternator...that didn't solve it. The original alt was really old so having a new one isn't the end of the world. Also during all this, the master switch was replaced.
But, the mechanic said they found that the rectifier? was bad and replaced it. They said the amps were just fine for their sunup. Later that day, I needed to add the capacitor to the Alternator since the original ones wire broke. After I added that, I did a run up and the ALT light was on and no amps showing at the amp meter.
I should note, I'm doing all this with the oversight of my A&P - since it is the weekend he was OK with me troubleshooting this.
In my service manual, I read that I needed to disconnect the field and + wires from the alternator and then with the master on, check each one with the VOM. The field has 11.59 volts and per the service manual, any voltage signifies that the circuit is good.
The + had no voltage and per the manual, I was to trace the circuit and when I found ~12 volts, I would have found the item needing replaced.
Well, from what I can see, the + wire from the alternator goes to the back seat and to the rectifier. The wire from the battery to the rectifier has 12 volts..the wire from the rectifier to the alt is zero. Bingo? Still the rectifier?
Would this really go out? The mechanics replaced it once and per the manual, it is the cause...but my mechanics are telling me it is OK.
Also, I'm thinking that since the field wire had 11.5 volts, the field circuit (voltage regulator and over voltage relay) is/are ok.
I attached the picture from the parts manual...does anyone have any thoughts?
Thanks, Allan
View attachment piper part.pdf
So I have a new Alternator...that didn't solve it. The original alt was really old so having a new one isn't the end of the world. Also during all this, the master switch was replaced.
But, the mechanic said they found that the rectifier? was bad and replaced it. They said the amps were just fine for their sunup. Later that day, I needed to add the capacitor to the Alternator since the original ones wire broke. After I added that, I did a run up and the ALT light was on and no amps showing at the amp meter.
I should note, I'm doing all this with the oversight of my A&P - since it is the weekend he was OK with me troubleshooting this.
In my service manual, I read that I needed to disconnect the field and + wires from the alternator and then with the master on, check each one with the VOM. The field has 11.59 volts and per the service manual, any voltage signifies that the circuit is good.
The + had no voltage and per the manual, I was to trace the circuit and when I found ~12 volts, I would have found the item needing replaced.
Well, from what I can see, the + wire from the alternator goes to the back seat and to the rectifier. The wire from the battery to the rectifier has 12 volts..the wire from the rectifier to the alt is zero. Bingo? Still the rectifier?
Would this really go out? The mechanics replaced it once and per the manual, it is the cause...but my mechanics are telling me it is OK.
Also, I'm thinking that since the field wire had 11.5 volts, the field circuit (voltage regulator and over voltage relay) is/are ok.
I attached the picture from the parts manual...does anyone have any thoughts?
Thanks, Allan
View attachment piper part.pdf
