Charging Issue

[Crew Man]

Hi guys, 05 VZ SSV Crewman LS1. Cold start, dash voltmeter reads 12 volts at idle, checked with Voltmeter at battery 11.97 volts. If l turn it off and leave for 3 minutes, voltmeter reads 14 volts. Replaced Alternator and battery with new ones, same problem. No problem during the day with multiple stops/starts. It’s always that first start up for the day. Any ideas? Thanks in advance.

 

[lout]

was it a genuine alternator fitted
vz use a smart alternator controlled from ecu

 

[Crew Man]

was it a genuine alternator fitted
vz use a smart alternator controlled from ecu

A JAS Oceania ANJ105. Thing is, with the old alternator, it was doing the same thing.

 

[Fu Manchu]

Go through and clean earths.
Check condition of battery harness overall. Positive and negative.

 

[Crew Man]

Thanks Fu. Have cleaned terminals and earth's. Got me stumped, why does it only happen on the first start of the day? Been to 3 separate mechanics/auto electrical shops who have no idea why. Frustrating.

 

[lout]

if on 1st start volt gauge reads around 12v and you then go for a drive without cycling key switch does voltage increase or just stay around 11.8-12v for the whole trip

 

[Crew Man]

Stays on 12 volts the whole time.

 

[lout]

try turning to ignition on without cranking (reds)
wait 30 seconds , then turn off,
then start engine like normal

 

[Crew Man]

Cheers Lout, your advice seems to have worked this morning. But why?? Lol

 

[lout]

when alternator is functioning correctly do you see other voltages besides 14
i assume it is similar to ve with a wide range of possible voltages
especially during a long drive it should drop down to high 12's

But why??

that is the mystery
looks like ecu has an issue
you will need a high end scan tool to monitor field request at ecu when ecu is cold
and then when warmed up