When I am checking battery voltage at idle with no accessories on, it is 14.4 stable. When fully loaded, it bounces between 12.2 and 12.35 volts. The alternator is about 1 year old and is made by ToughOne from Advance Auto. The car is a 2005 Honda Civic. Is load voltage not too low?
Normal alternator load voltage?
- Thread starter Avery4
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Yes that load voltage is failing. You should "almost" never drop below about 13v when loaded. Some vehicles drop to around 12.8v, but anything less than that and your actually discharging the battery slightly while running which will eventually kill the battery.
How are you taking measurements?
How are you taking measurements?
Originally Posted By: Rand
try doing the measurements at 1500rpm or so.
Some alternators will cut in at a slightly higher rpm.
Yup this.
A 120 amp alt has its rating at cruise RPM, only makes around 35 amps at idle. You can use this up with the HVAC fan, lights, rad fan, AC, and you'll dip in volts until you start running off the battery.
try doing the measurements at 1500rpm or so.
Some alternators will cut in at a slightly higher rpm.
Yup this.
A 120 amp alt has its rating at cruise RPM, only makes around 35 amps at idle. You can use this up with the HVAC fan, lights, rad fan, AC, and you'll dip in volts until you start running off the battery.
Originally Posted By: Avery4
When I am checking battery voltage at idle with no accessories on, it is 14.4 stable. When fully loaded, it bounces between 12.2 and 12.35 volts. The alternator is about 1 year old and is made by ToughOne from Advance Auto. The car is a 2005 Honda Civic. Is load voltage not too low?
Why did you replace the alternator in the first place?
Your car has an Electrical Load Detector in the fuse box that is designed to work the exact opposite of what you see:
Light load: ~12.65 VDC.
Heavy load: ~14.4 VDC.
I suspect that your cheapo alternator isn't playing nicely with the ELD. You need to get a better one. And a year is about what you can expect from a parts-store (gag) alternator.
When I am checking battery voltage at idle with no accessories on, it is 14.4 stable. When fully loaded, it bounces between 12.2 and 12.35 volts. The alternator is about 1 year old and is made by ToughOne from Advance Auto. The car is a 2005 Honda Civic. Is load voltage not too low?
Why did you replace the alternator in the first place?
Your car has an Electrical Load Detector in the fuse box that is designed to work the exact opposite of what you see:
Light load: ~12.65 VDC.
Heavy load: ~14.4 VDC.
I suspect that your cheapo alternator isn't playing nicely with the ELD. You need to get a better one. And a year is about what you can expect from a parts-store (gag) alternator.
Originally Posted By: Tegger
Originally Posted By: Avery4
When I am checking battery voltage at idle with no accessories on, it is 14.4 stable. When fully loaded, it bounces between 12.2 and 12.35 volts. The alternator is about 1 year old and is made by ToughOne from Advance Auto. The car is a 2005 Honda Civic. Is load voltage not too low?
Why did you replace the alternator in the first place?
Your car has an Electrical Load Detector in the fuse box that is designed to work the exact opposite of what you see:
Light load: ~12.65 VDC.
Heavy load: ~14.4 VDC.
I suspect that your cheapo alternator isn't playing nicely with the ELD. You need to get a better one. And a year is about what you can expect from a parts-store (gag) alternator.
ElD and alternator new. Alternator voltage regulator failed and over charged, killing the ELD. Thank you for your helpful input.
Originally Posted By: Avery4
When I am checking battery voltage at idle with no accessories on, it is 14.4 stable. When fully loaded, it bounces between 12.2 and 12.35 volts. The alternator is about 1 year old and is made by ToughOne from Advance Auto. The car is a 2005 Honda Civic. Is load voltage not too low?
Why did you replace the alternator in the first place?
Your car has an Electrical Load Detector in the fuse box that is designed to work the exact opposite of what you see:
Light load: ~12.65 VDC.
Heavy load: ~14.4 VDC.
I suspect that your cheapo alternator isn't playing nicely with the ELD. You need to get a better one. And a year is about what you can expect from a parts-store (gag) alternator.
ElD and alternator new. Alternator voltage regulator failed and over charged, killing the ELD. Thank you for your helpful input.
It is common to have to blip the throttle to over 1100 rpm on the 80 and 90 amp alternators in the E28 just once to wake up the regulator. OTOH, you can replace the regulator/brush pack with out removing the Alternator. No load, they would put out 14.1 V. The ? alternator in the Rat puts out 14.5 V at idle. It is lightly optioned. No AC, manual everything. Just lights an a 65$ single DIN radio. It had a new belt on it when I bought it
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