I have a 99 4Runner with 280,000 miles. Started it up tonight and everything was fine until I turned the headlights on and it completely shut down no electrical power at all. no mods at all and the battery is good. Any ideas?

 

Happy new year and welcome to the forum.
May I suggest that you put Model-Year-Engine-Transmission-Trim on your signature? It will save everybody time in the future. Schematics and parts vary with engine.
How do you know battery is good?
Got a multi-meter? Next only to our senses, that is the most important electrical diagnostic tool.
Could be a bad short that blew a main fuse, not just the headlight fuse.
Checked the fuses? Need a multi-meter for that. Visual may not be enough to see a problem.
What was the last what was the last thing you did that could disturb wires / open insulation / make wire with worn-out insulation touch ground?

 

My apologies, I was in a hurry last night. I saved a signature with the info you requested but it's not showing up for some reason. I have a 99 4Runner SR5 Sport, 3.4L, Automatic, 2WD. About a month ago I went to start it and as soon as I turned the ignition over everything shut off. So I took the battery out and had it checked at the local Autozone and cleaned the cables and terminals. Battery checked out OK and I haven't had any trouble since then until last night. Other than that I haven't done anything to it. I do have a multi-meter.

 

I'd still suspect cables first. They can be tricky. The terminal bolt treads can strip and terminal will not tighten. Ground connection can come loose or corrode. Cable cab corrode inside the insulation (look for bubbling in the plastic) and die that way. A test light is actually the better tool for this. A meter can show a connection as good but it won't pass real current, just enough for a meter reading. Start with the positive post in the main fuse box to the negative battery post. Then do the engine hoist hook to battery positive. Odds are one of those will not light, and that will tell you which side has the fail. If both do light, issue is one of the big fuses in the box.

 

Thanks, it does behave like it has something to do with the cables. I'll have to get a test light.

 

Since u already have a multi-meter, forget the test light. Multi-meter will tell u mo​​​​​re.

 

I hate it when I research something on any of these forums and the OP never posts the conclusion so I;m going to wrap this one up. I had time to go though the 4Runner yesterday and it ended up being a faulty battery cable. Thanks for everyone's help.

 

Ding, ding, ding.

 

Not when you are chasing a totally dead connection issue, it won't.

Save it for where it is the right tool.

 

Me too, thanks for the follow up