Red Battery light came on today Topic is solved

Post by **Blacklab467** » 02 Mar 2021, 12:39

My car must have been feeling unwanted and neglected that I was looking at another car so it threw on the red battery warning light on the dash! I assume this means that the battery is not receiving a charge and will go out with the multimeter and investigate it this afternoon.
Any tips or advice or flowchart to pinpoint the problem? The battery is about 4 years old. I'm thinking the alternator has probably just died? The car will still start so I'll start by measuring the voltage at the battery. Any other ideas would be welcomed! Thanks.

Post by **abscate** » 02 Mar 2021, 14:05

Quick diagnostic is to measure B+ at battery , then start and look for a 1.5-2.0 V lift.

Often can be fixed with just a voltage regulator or take the beast to a auto electric shop for $100 rebuild. Keep that good Volvo core part

Post by **oragex** » 02 Mar 2021, 15:57

Voltage at battery with the engine running should be above 14v now in winter time. If you rather get 12v-12.5v it means either the alternator regulator is kaput, either a power cable has an issue somewhere. It means you are running now on battery alone, depending on its condition, you may still drive for another 10-30 miles or so. Bosch makes the regulators and you need to get the one for 01-03 because the 04-09 ones are different and will not charge past 13.5v which will kill the battery in the long term

Post by **Blacklab467** » 02 Mar 2021, 17:16

Thanks guys, 12 volts at battery, same when engine running. I took the Dirtymax to the auto wreckers and got a used one off an '02 S60, I wonder if I shouldn't take it apart and clean up the slip rings and brushes......its quite dirty and looks like it has been rained on quite a few times. Does anything go wrong with the pulley clutch thing, Can it be removed to disassemble the alternator with an impact like a traditional alternator?

Post by **Blacklab467** » 02 Mar 2021, 17:26

The alternator I got today is an original equipment with a Bosch regulator off a smashed up S60 with 140,000 kms.

Post by **Blacklab467** » 02 Mar 2021, 18:10

Ok so I just went out to the garage to check voltage at the B+ on the alternator, started the car up after the charger being on for a few hours and I have 14.6 Volts at the B+ and the battery now.......and no battery light!
I get a little nervous when things like this happen, cars don't fix themselves! I think I will just drive it for a couple days around town and see what transpires, maybe check some grounds? It seems like this issue isn't a "hard" failure but rather, intermittent. I'm open to ideas.
I have what looks to be a good spare alternator now at least!

darylrobert · Post by **darylrobert** » 02 Mar 2021, 18:33

your lucky to get any warning, my alternator had an intermittent fault (diode failure) after 1hr of driving and NO warnings. Highly recommend getting a hide away battery alarm, ive set mine to chime at 12v, yes it does chime (like a truck) if i dont start the car immediately and car hasnt been started for a few days without trickle charger.

I think the volvo "low battery" message is set at 10v or something really low.

Unless you have tow truck cover, then you dont need to worry.

Post by **Blacklab467** » 02 Mar 2021, 19:23

I think its an intermittent issue, as I said the first time I checked it with a voltmeter running it was only at 12 V ( battery voltage) so nothing coming from the alternator. I'll see what tomorrow brings and report back!

Post by **RickHaleParker** » 03 Mar 2021, 00:15

Blacklab467 wrote: ↑02 Mar 2021, 19:23 I think its an intermittent issue, as I said the first time I checked it with a voltmeter running it was only at 12 V ( battery voltage) so nothing coming from the alternator. I'll see what tomorrow brings and report back!

Have you cleaned the battery terminals and the B+ wire connectors? It would not be the first time a poor connection did this.

Post by **abscate** » 03 Mar 2021, 02:53

Negative post off first before ANY cleaning of positive terminals!