Battery Voltage Question

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Aug 11, 2010 | 06:56 PM

Striderwv

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From: Almost Heaven

Battery Voltage Question

Is it normal on start up to have voltages around 11.8+ for a few seconds to maybe 30 seconds (stone cold) before you get to 13.5+? I set my alarm at 12 volts and my insight sings to me a little every time I start up. Thanks.

Aug 11, 2010 | 07:08 PM

havns3

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From: northeast missouri

the insight montiters voltage? i got to find that.

Aug 11, 2010 | 08:04 PM

Striderwv

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From: Almost Heaven

The CTS does. How may PID's do you have?

Aug 11, 2010 | 08:39 PM

Curt's05

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my voltage goes down to around 11.00 volts cranking via insight. my running voltage was @ 13.00 so this with some good advice i replaced my alternator,
and am around 14.00 volts.

Aug 11, 2010 | 08:42 PM

sammy77

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Joined: Oct 2007

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From: Illinois

Quote:

Originally Posted by Striderwv

Just keep a close eye on things for now. What is the voltage when its running?

Aug 11, 2010 | 08:57 PM

m-chan68

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From: Woodbridge, Ontario, CA

Before you jump the gun and replace your alternators guys, bear in mind the glow control module does draw some current for at least 30 seconds after the engine is started, long after the wait to start light shuts off.

Aug 11, 2010 | 09:03 PM

Zmann

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From: AZ

Quote:

Originally Posted by m-chan68

exactly ,, so what u see is normal ,, best to leave any high amp draw items off for that glowplug duration also if possible ,, both the cts and older insight will monitor bat voltage

there is also rummored to be a pcm strategy in place that doesn't signal the alt to produce full potential untill the glow plugs are done .. that has yet to be fully verified however ,, but seems to make sense

I run a aftermarket dc power alt ( big frame) rated at 190 amps and it puts out way more at idle than the stocker ,, I still see the voltage issue untill the plugs shut down

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Aug 11, 2010 | 09:21 PM

Zmann

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From: AZ

what strategy do you have?

Aug 11, 2010 | 09:25 PM

#10

rocky1074

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From: Inverness, Fl

Quote:

Originally Posted by havns3

the insight montiters voltage? i got to find that.

It's listed as mod volts on the insight menu. The 03's do not support volts. Had to get a volt meter

Aug 11, 2010 | 09:45 PM

#11

cheezit

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From: N. Fort Worth, tx

the alternator will not charge till the gpcm timer has turned off. aprox 2min timer.

Aug 11, 2010 | 11:59 PM

#12

dchamberlain

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From: Scio, OR

Quote:

Originally Posted by Zmann

there is also rummored to be a pcm strategy in place that doesn't signal the alt to produce full potential untill the glow plugs are done .. that has yet to be fully verified however ,, but seems to make sense

I've heard this a lot. But, according to the wiring diagrams I have, there is no connection to the alternator from the PCM, except on dual alternator engines.

So I don't know how that'd be possible.

Edit: Upon further reading, it appears that on dual alternator setups, the voltage regulators on both alternators are powered by the PCM. Apparently the lower alternator is shut off by the PCM until the GPCM cycles off. It doesn't say why.