Battery light came on Dashboard

Battery light came on, on the dashboard and my radio cut out while driving home. A couple minutes later the light went off and everything back to normal.

First time i've ever had this happened. Anyone know whats up? Alternator going out?

 

Low battery voltage is what that means. Any auto parts store will test your battery for free and tell you if it’s bad. I’d start there

 

If the battery tests good, then check the alternator

 

this battery is relatively new (1-2 years old) so i don't think it would be an issue. how do i check the alternator?

 

With a volt meter or old school way of starting the truck then disconnecting the negative cable at battery. If it shuts off, alternator is weak or bad. If the truck remain running, good alternator. Lol

 

I would also check and make sure that your grounds are actually grounded

 

This is happening to me, now, on a 2005 at 243k miles on the 2TR-FE (original alternator). I replaced the battery, light comes on/off. No corrosion in terminals or cables.

 

How is this done? I have a Scan Gauge that plugs into the OBD port. When I get the battery lite, the gauge reads low 12s. It's momentary, jumps back to 13.6. Yesterday the lite stayed on for 10-15 minutes. When I started the truck back up, lite on and no Scan Gauge information. Pushed the clutch in, revved the engine, all's well. The battery is 5 years old, truck is an '07 with 385k miles. I, too, thought grounds based on a tractor we had at work way back when. But I didn't do the fix and don't know how. Are they shown/listed in a manual?

 

If she is an 07 you need to be posting in the 2nd gen forum... people there are more familiar with that truck and its quirks.

 

The battery warning light is a bit misleading. It doesn't mean the battery is low.. it means the charging system voltage is low.. usually a bad alternator

Hook up a voltmeter across the battery, turn the engine on and see what the out-put is. Should over or around 13.5 volts. Turn some electrical loads on like headlights and fan blower and see if the voltage goes down. Rev the engine up and see if the voltage increases with higher rpms..

 

Before doing any of the above, do the most basic, disconnect and clean your battery terminals. I can't count the times this was the cause of multiple charging circuit issues. In one case the terminals were clean but the wire crimps were all gunked up.

 

Thanks for the tips. I'll try them and if to no avail, go to the Gen II Forum.

 

This is what happened to me with my 4runner last week. On a road trip, battery light came on and Scangauge showed voltage at around 11.5v give or take a few. After a bit, it would jump back up to 13.5/14v and the light would go away. Then come back. Eventually came back on and the voltage stayed low, kept getting lower. Surprisingly, I made it the whole 300 mile trip without it dying on me.

It was the alternator. At 271k miles the original one was worn out. Replaced it when I got to my destination with a new Denso unit and it's been running right ever since. Not sure how easy it is to get to on the second gens, but on the 3.4l v6 you just need a few basic hand tools (sockets) to replace it. Super easy. Took about 2 hours only because the new one was a bitch to fit into place, once it's in it just bolts right up.

 

My alternator went out at 243k, but each time the battery light came on, I'd hit the alternator with a hammer and it would start working again....light would go out.