Battery light flickering on startup

[E53fan16]

Hi guys,

I noticed Saturday that my battery light has been flickering on startup. It continues to do this now. Is this a sign for me to get a new battery, or is the alternator slowly on its way out?

I use a Bluetooth transmitter that plugs into the cigarette lighter up front that gives me my battery levels. Prior to starting the car, it's 12.5V and while the car is running it's 13.8V. This seems within range. I have a small road trip coming up this Thursday so just trying to get an idea of what may be going on.

Thanks in advance.

[itscoo2pyopants]

in my experience, battery light has always been an alternator issue.

[jsoto]

alernator. better safe than be stranded....especially in this heat !

[StephenVA]

Test DO NOT GUESS.

Tools Volt meter (digital) after confirming all the posts are clean and tightened including all the grounds in the trunk area. This will confirm no water in the well, positive cable has NOT been compromised by the explosive connector.
Read/Test at battery post in the trunk first. Reading engine off over 12.5 V?
Start engine, Read at battery posts. Over 13.5V?
Do a Voltage drop test on the cables. See image below. and video
https://www.youtube.com/watch?v=3-9oZuX6-Pg

Move to under hood jump post +, tight? Read Voltage engine running...over 12.5V and steady? Bring RPMs to 2500, reading?
Turn on all the accessories while reading voltage. Still above 13.5V? Steady? bring RPMs up to 2500. Steady or moving all over?

The RPM tests show regulator function with speed and load. Most of these alts die due to the regulator loosing connection at the slip ring or the reg going dumb. The voltage will bounce all over the place.

Options: If everything points to the alternator then look at the back of your alt and buy a NEW not rebuilt unit (Bosch or Valeo) unless you are willing to install and reinstall until you get a functional one. See all the other postings on charging issues and rebuilt alternators for examples of those who have tried the price path before you. Cheap is not the way to go. But as they say, it is your car, time, wallet, etc.....

[Fifty150hs]

Originally Posted by E53fan16

Hi guys,

I noticed Saturday that my battery light has been flickering on startup. It continues to do this now. Is this a sign for me to get a new battery, or is the alternator slowly on its way out?

I use a Bluetooth transmitter that plugs into the cigarette lighter up front that gives me my battery levels. Prior to starting the car, it's 12.5V and while the car is running it's 13.8V. This seems within range. I have a small road trip coming up this Thursday so just trying to get an idea of what may be going on.

Thanks in advance.

Every time my alternator has gone, it started with an intermittent battery light.

[E53fan16]

Thanks, guys. I'm going to drop it off at the Indy tomorrow.

How much should I expect to pay for an alternator job?

[Fifty150hs]

Originally Posted by E53fan16

Thanks, guys. I'm going to drop it off at the Indy tomorrow.

How much should I expect to pay for an alternator job?

Depends on whether you go with a reman. or new alternator. Job shouldn't take more than a couple hours.

[StephenVA]

Why would you pay a shop to do a quick test and replacement of an alternator? Lack of skills/time? The tools required will pay for themselves in one effort. Time required on you 3.0 application 2 hrs including replacing the drive belts as they are more than likely toast as well.

DIY costs: Alt $200, belts $40

Shop: $300/400 parts, Labor 2.5 hrs @ $125 per hr = $325 Totals $625 min.

Note: Pricing is based on real life not corner gas station skill sets

[E53fan16]

Originally Posted by StephenVA

Why would you pay a shop to do a quick test and replacement of an alternator? Lack of skills/time? The tools required will pay for themselves in one effort. Time required on you 3.0 application 2 hrs including replacing the drive belts as they are more than likely toast as well.

DIY costs: Alt $200, belts $40

Shop: $300/400 parts, Labor 2.5 hrs @ $125 per hr = $325 Totals $625 min.

Note: Pricing is based on real life not corner gas station skill sets

Unfortunately, lack of skills

Thanks for the feedback.

[jsoto]

depends if the OP has the water cooled alt or not . That's still like $4 for Bosch and $5 for Roundel brand, both reman though...