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what's the standard voltage?

CerealKiller

By CerealKiller,
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CerealKiller Veteran

CerealKiller

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What voltage should I be getting in a R32 (RB20DET)? I believe it should be at least 14V but I rarely get 14V :D My last car got a healthy 14.4V. Mine struggles with electrical load. If I turn on the a/c + headlights it drops it down to about 13.3V, if I brake it'd drop down to 13V :O

Any suggestions? I got my alternator replaced last year as it died, and I've got a 12 month warranty on it. Reckon it'd be worth getting it replaced?

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The Dan Grand Master

The Dan

Posted
Posted

No...those voltages are fine. 14.4 v is bordering on overcharge.

At idle with no accessories it should be between 13.5 - 14 v

With high beam on it should drop roughly 0.05 - 0.15 v

With A/c and highbeam on it should drop a further 0.2 v or so.

When you hit the accellerator it should recover to just under your idle unloaded voltage.

With all accessories on at idle, 13v is ok.

If you are reading a voltage of a handset or something of the like, you will find that there will be a difference between the voltage displayed and the actual voltage.

They are not terribly accurate but in most cases are within 0.2-0.3v

If it drops below 12.8 volts with all accessories on, then replace it.

If you have any doubts, take it back to whoever fitted the alternator and ask if they wouldn't mind re-checking it for you. I'm sure they won't mind.

Sumo Mentor

Sumo

Posted
Posted

Yeah, grab a multimeter. You may be just expiriencing voltage drop where your timer gets its source or earth from. I wouldn't be happy with my alt dropping to dead on 13V with a few of the accessories on. If the battery is fully charged I would be chasing 13.8V. If it is dropping work out how many things you have running (big stereo?) and see if your alt can handle it.

The alt I have on the r33 runs at about 14.5 Volts up front, by the time it gets back to the battery in the boot its down to around 14.2-3.

Sumo Mentor

Sumo

Posted
Posted

readings at where though? from the back of the alt whilst its running?

Check your earth leads, especially around the chassis earth. Do a simple voltage drop test on your earth lead. Same with the positive. When I say voltage drop test - as in from the Pos on the bat to the pos on the alt whilst under significant load. Should have a tolerence of about 0.3-4V if higher fix it, if lower, its good.

I could go on for hours, but finding a voltage drop can take ages.

Cheers

Sumo

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