Alternator going bad?

[Charliebrownwds]

Hello guys my 03 tb has a small issue. Upon start up the voltage remains under 14 volts after a few seconds it goes back up to 14v and it remains there. What could be the issue?

 

[xavierny25]

First things first, how are you keeping track of your voltage? If your going by the dash gauge that's not going to cut it.

 

[Charliebrownwds]

With an obd scanner im able to see the voltage drop.

 

[christo829]

What's the temperature where you are? If it's particularly cold, the PCM will suppress alternator output until the engine gets going, then lets it come up. If it does this even when warm, then something else is going on, like the temp sensor that talks to the PCM is giving the wrong reading.

Good Luck-

Chris

 

[xavierny25]

Chris made a good point. Another question what's the age of the battery? And have you had it tested?

 

[Charliebrownwds]

The battery is less than 6 months and i tested it and it is good. But now that you mentioned it it was particularly cold here in illinois. In the teens down to -15

 

[Sparky]

This is normal when the vehicle is really cold. The PCM will keep the alternator shut down for the first few seconds after start to let things stabilize, then it will kick the alternator in.

 

[Charliebrownwds]

Great thank you so much for the information. Very helpful you guys