Dash lights

Started my truck up in the garage and have dash lights. The moment I turn on my headlights the dash lights go off. 2013 Tundra. Help!

 

It's very likely your alternator died. If the battery is more than 4 years old, you might opt to replace it, drive it the shortest distance possible and have the alternator tested.

If you have volt meter and it shows less than 12.3 volts, or the headlights glow dim, charge the battery if it's newer. Otherwise replace and start there.

Note: if the alternator is dead, the charge indicator should be on in a gauge cluster but not always.

Leave every accessory off if driven or you might be walking if more than a few miles.

GL

 

Oh and don't buy a cheap rebuild. Look for a remanufactured alt from Denso. Toyota's are picky about this...

 

Could also have hit the dash dimmer switch. All the way down basically turns the dash lights off. With the headlights off the dash lights will be on full brightness

 

lol - I think I read that wrong! OP take advice from the PalmTree. I bet it's correct! -insert shame emoji-