Hi guys,
My Autometer gauge and log viewer(in Megasquirt) always were reading low like in the 12.8V area. I just had the alternator and external regulator checked out at a local reputable shop. The alternator reads 14.2 with no load and the reg is also good. Its a 55amp Porsche alternator.
Why is this? I've never had a charging problem it just always bothered me that they read lower than the thing checks out.
Just to double check............where should I be reading my voltages from? Off the external regulator or?
Alternator is 14.2v but gauge & log read 12.8? Reg is good
- panel
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Alternator is 14.2v but gauge & log read 12.8? Reg is good
'65 Bus with a JDM Subaru EJ20 Turbo
Built by Germans powered by Japanese and brought together by Canadians
Built by Germans powered by Japanese and brought together by Canadians
- fastback
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Re: Alternator is 14.2v but gauge & log read 12.8? Reg is good
u have voltage drop over cables , fuses etc. under load , so reading 12.8V at Megasquirt is normal,
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Re: Alternator is 14.2v but gauge & log read 12.8? Reg is good
Start at your battery and measure the voltage at connection points progressively as you work your way towards where your ECU is powered. You should be able to find where the voltage drop is.
- panel
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Re: Alternator is 14.2v but gauge & log read 12.8? Reg is good
Curious what gauge wire from Alt to starter should I have/use?
'65 Bus with a JDM Subaru EJ20 Turbo
Built by Germans powered by Japanese and brought together by Canadians
Built by Germans powered by Japanese and brought together by Canadians
- david58
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Re: Alternator is 14.2v but gauge & log read 12.8? Reg is good
If you check the voltage on the wire at the alternator that is battery plus, and ground on the engine with the car running, with a digital multi-meter with as much load as you can put on it. (All lights on and accessories too.........) then you can see how much the system is actually charging. Like said above move the test leads further from the source to see if there is a voltage drop.
Hot, humid air is less dense than cooler, drier air. This can allow a golf ball to fly through the air with greater ease, as there won't be as much resistance on the ball.
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Re: Alternator is 14.2v but gauge & log read 12.8? Reg is go
My 55 Amp Bosch alternator (with no load) read 14V at B+ and 13.9 V at the other end of the fuse terminal.
I am using 2 quarter inch copper wire (exclude the pvc covering) thick wire (not sure what gauge size) that runs from B+ all the way to the front fuse panel and the 2nd wire to the battery + terminal plus the original quarter inch wire from the batter to the fuse panel--(in parallel with my additional quarter inch wire).
I am using 2 quarter inch copper wire (exclude the pvc covering) thick wire (not sure what gauge size) that runs from B+ all the way to the front fuse panel and the 2nd wire to the battery + terminal plus the original quarter inch wire from the batter to the fuse panel--(in parallel with my additional quarter inch wire).