Main fuse blown?

Background. 2011 Tundra 5.7l.
My wife went to start it, didn’t crank. Tried a second time, cranked but didn’t start. I checked the battery and connections were all corroded.
Got a new one just in case, reconnected every correctly. Put a charge on it just to be sure.

Tried to start and once this ignition started, heard a click and all electrical went dark. Wife was watching the battery but said something popped nearby. Did my main fuse pop?? Will try to attach picture.

I suspect some rats were inside the hood, after seeing some dropping but no obvious signs of wires chewed.

When the battery is connected, all fuses have 12V to them, except the set of 9 on the right inside of the box. Same with the ones inside the cab.

When the ignition key is in, dashboard illuminates, but near the fuse box it clicks and the set of 9 fuses have like 300mV.

Any ideas? Does it look like the main fuse needs to be replaced and any potential of a short somewhere?

Thank you,

 

Are you 100% sure the battery was connected with the correct polarity? Hooking it up backwards is a very fast way to blow out the main fuse, seen it happen before.

The mainfuse is hard to see down inside. Use a flashlight to look straight down inside the little windows and see if any of it looks black/burned/broken.

 

Thanks for the reply Jeff. Yes 100% sure the battery was correct. I just spent an hour taking the main fuse block out to replace it and it appear fine. I bought a power probe and will be checking all the fuses and check the diagrams. One of my concerns is that the last time I checked (a couple of days ago), the fuses on the lower right of the box all at ~300mV only and not 12V and a relay kept clicking. I will find out which one right now and update the thread with my findings.

 

Oh look at the short pin in the fuse box, its a "jumper" that looks like a fuse. They remove it for shipping the vehicle. It is need to pass power through to part of the fuses and fuse box

 

Well, I don’t know if this is embarrassing or not. I replaced the battery, and replaced the terminal connectors with a new set (old was corroded). Was able to reconnect everything and it started. Tried again 5 minutes later and nothing. Went completely dark, no power on all fuses.

Took a cheap voltmeter and battery shows 12.56V, but the cable right off the terminal shows 3.5V. There is a huge voltage drop on the connection between the battery terminal
and the main cable off the block. Must be a cheap one. Going to replace it with one from the auto shop.

 

Same issues! Did you ever solve?