Volvo Forums banner
1 - 3 of 3 Posts

· Premium Member
228 Posts
It's a 12v system, but I think anything in the 13.8 - 14.2 Volt range is healthy. I would check it and record your readings. If it is remaining steady over a period of time it's probably ok. If you notice a continue deterioration then you likely have another issues such as alternator or battery failure.

· Registered
2 Posts
Discussion Starter · #3 ·
Thanks for the reply.

The battery is fairly new and was at 12.31 Vdc today and the car has net been used for over a week. After starting the alternator was putting out 13.8 V today but the "GEN" light did not go out for about 5 minutes. The "GEN" light staying on after starting is what got me started on this investigation.

The voltage measured at the battery during the start sequence was:
After sitting for 7 days : 12.31 V
With key in on position, head lights come on: 12.0 V
During start : 10.8 V
Immediately after starting: 12.0 V
It took about 15 seconds before the voltage increased to 13.8V
It stayed there even as I changed engine RPM.
"GEN" was on for about 5 minutes then went out. I don't know what the voltage at time was.
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.