No electrical power to cab

My 08 Tundra lost all electrial power to the cab after I unhooked my trailers light hook up. Ive checked all fuses & relays under the hood & replaced all in cab fuses and still no power. I got a new ignition switch today. Going to replace tomorrow. Anyone with any similar issues and if so what was the fix

 

Sounds like the main fuse. Got a multimeter? Check your battery voltage. Check for power going into the fuse box.

also, just for fun check for corrosion on the battery terminals.

 

Yes I have a multimeter and battery voltage is 12.4V I am getting readings between 8.2V-9.4V on my fuses in engine compartment and the light barely comes on when checking fuses in the cab. Ive replaced the ignition switch this morning and still nothing. I have tested some of the relays with a multimeter and most relays the reading went from OL too 0.00. But my starter relay reading never changed from OL.

 

You should be reading at least 11-12 VDC (fully charged battery should be 12.6 or a little higher) on the fuses in the engine compartment. Are you sure that the main fuse in the engine compartment fuse box is not blown?

 

Don't forget to check your grounds and the wires/connectors between the battery and the main fuse box

 

Oh, and check your trailer light hook up. You might have something shorted to ground

 

I have checked the engine compartments main fuse and its good. I never even thought to check my grounds. I'll check the grounds, wires and connectors today. Although I did replace the ACC Cut Relay along with replacing a few other relays and fuses that just looked rough but not blown and got power restored shortly. that i until I went to start it and either a fuse blew or the acc relay is out again. Im just at a loss. I get all my repair info from Identifix and try to do all the repairs myself. I have to say that its been an awesome truck. shes pushing 480,000

 

Damn, 480k Anyway, be sure to check out the trailer light hookup. You said power to the cab was lost after disconnecting the trailer light connection, something there could be the cause. You could also reconnect it and see if power returns.

 

Thank you vmkeith for mentioning checking the trailer light hook up. It never even crossed my mind to even start looking there, because the power for the trailer lights obviously come from the fuse box. I guess I was just dead set on it being 100% a fuse or relay, but I can honestly say that I'm 100% glad I didnt take an interest in auto mechanic in school lol.

 

Not a problem at all. Happy to help, especially if it leads to fixing the issue.