92 Camry battery good but no current

[WRG]

My wife drove to the store and when she got in the car and turned the key the dash lights lit like normal and when it went to engage the starter the electric died. This is a 1993 4 cylinder Camry. I assumed a bad battery or loose connection. The battery is good. Tried cleaning and tightening the clamps. Used a jumper cable. There is no power, period. Not even with a jumper cable attached from another car. No headlights, dashlights, no sound. Before I start taking things apart, it looks like the positive wire runs down and maybe T's off under where the air filter box is. If it does I suspect a bad or burned connection in there.

I've checked on this site but didn't find anything just like it. Any help is appreciated and I appreciate this site because of the good Toyota and car knowledge here. Thanks

[Toysrme]

Check your main relay. Then main fuse.

[WRG]

After I took the air breather box out and traced the wires I found a ground wire that wasn't attached but had been wedged in under the battery tray. I looked at a 6 cylinder Camry and saw that the end connection was on a bolt at the transmission so I did the same and it all works great now. The engine needs a good ground I guess. Just thought I'd let you know what I found.