Could this be an alternator?

[4runsport]

Quick question and yes I used the search function haha

2002 Runner with about 178k on it. When im at a traffic light or stopped at night with my headlights on at night I can see that my headlights are not as bright as usual. Only slightly noticeable until i put my foot on the gas and they become brighter. You can literally see them brighten up a bit. Now at almost 180k do you think its just my alternator giving out? I need to do all the outer belts and timing belt etc.. soon. Probably best to change it at the same time? When I get the truck serviced they usually check the charging system and say everything is ok but sometimes its hard to believe. :redbrick:

 

[BigBluePile]

You have to remember that at idle that alternator isn't pumping out amps. Could be as simple as cleaning your battery connections and double checking all your grounds.

What is your idle at?

 

[4runsport]

You have to remember that at idle that alternator isn't pumping out amps. Could be as simple as cleaning your battery connections and double checking all your grounds.

What is your idle at?

I thought during idle the alternator is putting back what the accessories are using? Especially after the draw the startup takes away. Idle is normal and seems ok. Battery is only a few years old and connections seem good. I know electrical problems are like poltergeist and no two are the same. I just can't think of anything else that could be causing the dimming both to the headlights and the dash cluster lights inside until I step on the gas.

 

[3rzrunner]

You have to remember that at idle that alternator isn't pumping out amps. Could be as simple as cleaning your battery connections and double checking all your grounds.

What is your idle at?

.......

 

[Chewbacca]

Get a multimeter and check the ALT. output. if its below spec that is most likely your problem. I wouldn't doubt if there is some corrosion inside the connections though.

 

[LittleCaesar]

ALt output should be between 13.3 (battery fully charged) and 14.3 (initial start). Check at the battery terminals with a DVM with the engine running.

I'd start withe battery, making sure it is at least 12.3v with the engine off.