Last week i washed my engine with simple green and a garden hose. Then my battery and brake light came on. So i put a new alternator in it. The charge and brake lights went out. Now my battery will not hold a charge. I did not have any starting problems before the new alt install. I dont know how old the battery is i bought the truck about two weeks ago. I guess I will take my battery to auto zone tomorrow and get it tested. I was just wondering what you all thought. By the way it is a 94 4runner 3.0 V-6 5 speed.

 

I had the exact same thing happen after cleaning motor, put new alt in, and lights went out for a week, yesterday they both flashed for a second, and nothing since then. I don't have starting problems though, so the battery seems ok.

 

Those lights are supposed to come on every time you start the truck, to show they're working and they should turn off once the engine is running, they're nothing to worry about if the truck starts up fine unless they stay on. There's a problem if they DON'T come on when you start up, which usually means dead battery, bad connection, or burnt out bulbs. My truck came with an 8-year old battery and a cracked alt housing and otherwise destroyed alt, the lights would barely come on and would actually flicker out when starting even after I had the alt rebuilt, no such trouble with the new optima yellow top under the hood though!

 

yeah, when mine came on the other day, they both stayed on longer than the normal amount of time when you first start. I haven't had an issue since, so I am hoping it was something that got wet having to do with the circuit that turns on the two lights.

 

I'd suggest you go get your alt checked if you're worried about it.