Ok intermittently my brake light and charging light will come on together. Sometimes the stay on for a few seconds other times they just flash. If I have the lights on when it does this they will get brighter like the alt is charging more. It will affect anything electrical like it throws more voltage. It knocked my radio out and when Im running the heater it revs up more too. I've checked for loose wires but can't seem to find anything. Any ideas guys. Thanks

 

Test your alternator and battery. It could be a combination of both, but I bet your alternator brushes are about gone. Replace them and then check your battery again to make sure your battery is good.

Brushes at the dealer are less than $20.00

That is of course you still have the stock alternator, if not then...you should by a stock alternator. Toyotas work best on OEM electronics.

 

Mine did this, turned out the wire bolted onto it was loose and corroded. Tightened it, then broke the stud, then had to do a little bit of work lol.

 

my truck was doin that also... i replaced the brushes in my alternator, and now the lights dont come on anymore... for something alittle cheaper, but alittle more work, you can just get the brushes for about 5 bucks... i think the 20 dollar part is for the brushes and the holder assemble... just my 2 cents...

 

Same thing just happened with my wife's 4runner, I put new brushes in and took pics and made a post of it.

https://www.yotatech.com/forums/f131...uy-one-224509/

It fixed it and was way cheaper than buying another.

 

my truck was doing that for about 2 months, just randomly...turns out the alt. and battery both went. id get them checked out and replace wichever one is bad