Power Surge Problem (Maybe)

[BlownAway]

After I have been driving for about 20min my battery light will come on with my brake light, if on the ac blows harder interior lights get brighter and my fuelpump gets louder. Any suggestions on what I should check. Thanks

 

[toybreaker]

This sounds like an alternator issue.

If you can measure the voltage at the battery, I would go there first.

Resting, it should be 12.5ish.

Engine running, it should be 14ish.

With the battery lite on, it may read substantially higher. (I've seen as high as 18v.... WTF )

Compare these readings with a reading taken at the alternator + post. If they vary more than 1/2 volt, you may have a harness issue. If they match pretty closely, and are excessively high, it's time for a new alternator.


This would also be an excellent time to check your battery terminals. They should be clean and tight, as should any, and all, wires attatched to them.

Also, checking the battery electrolyte level would be a very good thing to do. There's a cause/effect relationship between overcharging the battery, and the electrolyte level being low.

Running the battery level low due to overcharging can lead to major issues, from boiling the battery acid out everywhere,... all the way up to overheating/shorting the battery plates together, and creating some major trauma. (there was a thread on this a while back)

Please post back your voltage readings.

There seems to be a lot of charging system issues occuring lately, and I've been noticing that many of them are aflicting cars with relatively new chain store alternators...Please take note of this, and think twice about where you buy your parts from.

An easy, albeit expensive, option is the dealer....

In addition, almost every town of any size will have a reputable automotive electrical specialist. For a nominal fee, he can test your system and repair/rebuild/replace any components that require attention. Just ask the local general repair shops who they use for electrical troubleshooting/component rebuilding, and you'll find the right guy. One advantage of this approach is if you have any problems in the future, he'll be there to assist you.

... and it is a dsm, so you will have further issues..

Good luck, and let us know what you find.

 

[steve]

In addition, almost every town of any size will have a reputable automotive electrical specialist. For a nominal fee, he can test your system and repair/rebuild/replace any components that require attention. Just ask the local general repair shops who they use for electrical troubleshooting/component rebuilding, and you'll find the right guy. One advantage of this approach is if you have any problems in the future, he'll be there to assist you.

This is my first choice for dealing with alternator problems. The small shop will most likely provide you with a better quality product than any chain store replacement. I don't care for lifetime warrenties that really mean I'll be replacing an alternator every couple of weeks until I get one that works and when it goes bad I get to start over again.

Steve