Acts like alternator is bad, but battery light does not turn on while driving

[ivanbliskavka]

Hello, very strange problem, Tried searching the forum, got nothing, please help.

Its a 94 accord 140k miles. A few days ago the car just shut off, no electrical working. After the key was removed hazards worked, but dimmed and died shortly. After the battery was charged, the car worked normal, about 1.5 days later, same situation.

The strange part is, when just the accessories are on, battery light is on, when you drive light is off, acting like it is not the alternator.

I am afraid that it is not a problem with the alternator because of the way the lights are working. Is there anything else to consider, before swapping the alt?

[mpumas]

Its probably the alternator not providing sufficient voltage to charge the battery. The voltage regulator is part of the alternator, so if you replace the alternator, you get everything. About 140K, the problem usually centers around the slip rings and brushes. When they wear out, things don't work right.

[vicchang]

Originally Posted by ivanbliskavka

Hello, very strange problem, Tried searching the forum, got nothing, please help.

Its a 94 accord 140k miles. A few days ago the car just shut off, no electrical working. After the key was removed hazards worked, but dimmed and died shortly. After the battery was charged, the car worked normal, about 1.5 days later, same situation.

The strange part is, when just the accessories are on, battery light is on, when you drive light is off, acting like it is not the alternator.

I am afraid that it is not a problem with the alternator because of the way the lights are working. Is there anything else to consider, before swapping the alt?

I strongly feel it's the alternator. Use a meter to measure the voltage at the battery with the engine running. It should be around 14V. If not, it's your alternator.

Most common alternator problem is the brush. The original brush should last 140 - 170 k miles. If you know how to take apart an alternator, you can check the length of the brush. You can just replace the 2 carbon brushes if it's worn. Cost around $5- $10.

If it's not the brush, suspect the regulator. You can replace it alone also.

[ivanbliskavka]

We opted to just get a new alternator. Will see result after it is installed in a few days. I was just worried that the problem was something else.

Thanks for the help.

[kicker1_solo]

Originally Posted by ivanbliskavka

We opted to just get a new alternator. Will see result after it is installed in a few days.

Good choice, that should fix your problem, let us know...

[blacknight]

More than likely it was the altenator. Probably replace the battery also just to be safe.
Many times, with a dead battery it's hard to tell if it's a problem with the altenator not charging the battery or the battery having a dead cell and not accepting a charge.