James Romano
Well-Known Member
As stated. I bring her up to a good cruise rpm... Maybe 11.80...almost 12.
Alternator rebuilt by NAPA... I test at the alternator field...same as battery. Engine to firewall ground is good.
Took off the VR and cleaned the terminals. Same readings
I did a lot of reading and found this from about 9 years ago... BUT didn't perform it as I'm not 100 percent this will find my problem. What does he mean by the output stud to test the alternator?
QUICK TEST
For a few quick tests of your charging system, simply buy a meter -- you need one anyway-- and with the engine warm, the battery "normalized" (ammeter centered after some running) and the engine at an RPM to simulate "low to medium cruise" then measure across the battery terminals. What you ideally want is more than 13.5, perfect is 13.8-14, or high end about 14.5. Higher or lower is cause for concern
If this is low, no charge, pull the field wire off at the alternator, and install a clip lead from the output stud on the alternator to the field terminal on the alternator. You should hear the alternator "grunt" and with the engine GENTLY brought up a little in RPM, the battery voltage should start to climb. Be careful not to ref the RPM too much, and monitor battery voltage. Do not rev enough to bring voltage over 15, 15.5.
If you get no output, check the voltage at the alternator stud. Should be close to battery. If you have battery voltage at the stud, but no charging voltage increase, you have something wrong in the alternator
If the voltage at the output stud is low, much lower than battery, you have a wiring problem in the charging/ output circuit, either the ammeter or the bulkhead connector is your no 1 suspects
If this test DOES show a marked voltage increase, you have either a wiring problem in the regulator/ field circuit or a bad regulator.
To check for that, unhook the wires from the regulator, and connect them with a clip lead, reconnect the field wire at the alternator. As above, the alternator should output "full tilt," and be careful of the RPM
If this test shows a charging increase, you need a regulator.
I'm wondering if the Alternator is bad and all they did was clean and paint it?
I'd like to jump into more checks... If anyone has good advice on this issue
Thanks
Alternator rebuilt by NAPA... I test at the alternator field...same as battery. Engine to firewall ground is good.
Took off the VR and cleaned the terminals. Same readings
I did a lot of reading and found this from about 9 years ago... BUT didn't perform it as I'm not 100 percent this will find my problem. What does he mean by the output stud to test the alternator?
QUICK TEST
For a few quick tests of your charging system, simply buy a meter -- you need one anyway-- and with the engine warm, the battery "normalized" (ammeter centered after some running) and the engine at an RPM to simulate "low to medium cruise" then measure across the battery terminals. What you ideally want is more than 13.5, perfect is 13.8-14, or high end about 14.5. Higher or lower is cause for concern
If this is low, no charge, pull the field wire off at the alternator, and install a clip lead from the output stud on the alternator to the field terminal on the alternator. You should hear the alternator "grunt" and with the engine GENTLY brought up a little in RPM, the battery voltage should start to climb. Be careful not to ref the RPM too much, and monitor battery voltage. Do not rev enough to bring voltage over 15, 15.5.
If you get no output, check the voltage at the alternator stud. Should be close to battery. If you have battery voltage at the stud, but no charging voltage increase, you have something wrong in the alternator
If the voltage at the output stud is low, much lower than battery, you have a wiring problem in the charging/ output circuit, either the ammeter or the bulkhead connector is your no 1 suspects
If this test DOES show a marked voltage increase, you have either a wiring problem in the regulator/ field circuit or a bad regulator.
To check for that, unhook the wires from the regulator, and connect them with a clip lead, reconnect the field wire at the alternator. As above, the alternator should output "full tilt," and be careful of the RPM
If this test shows a charging increase, you need a regulator.
I'm wondering if the Alternator is bad and all they did was clean and paint it?
I'd like to jump into more checks... If anyone has good advice on this issue
Thanks