boogieboarder

My 4runner has an electrical problem, after about 10 minutes of driving the sound system will start going on and off, the headlights will get dimmer, the heater will stop blowing as hard, and the rear anti lock light comes on. Everything electrical slows down or stops working. It is starting to hesitate on startup too. I went to autozone and had them test the battery/alt and they said it was fine other than the battery being slightly low. So far its started every time but after a bit of driving those problems start happening. I don't know what it is, possibly a short somewhere in the wiring or something like that?
If i turn on the headlights the radio will turn off and things liek that happen and its all related. The voltmeter goes from the normal position down to about half pretty quickly once all these things start happening. The tachometer will also stop working correctly, it will jump or go down, etc or wont go above 2k rpms when the engine definitely is. I don't think its driving any different but possibly seems a little slower when accelerating but that could just be me imagining things.

Thanks in advance for the help.

camo31_10.50

Check your Grounds.

ToyMachine88

could be that your starter has a short in it or is drawing power from your battery when it isnt supposed to be. I broke down the other night- the meter on the dash was a little lower than what i remembered it being and everything started slowing down- wipers barely moving lights super dim radio not working engine wanting to stall- I have a brand new battery, new terminals and a new starter cable, so i immediately thought it was my alternator after checking and cleaning all my connections with no results. I was able to make it to Advanced auto before i broke down for good. Charged my battery overnight and went back - truck started right up- my buddy came out and hooked up the test machine, battery and alternator checked out fine- Found out that the starter can actually cause this issue tho it doesnt seem like it would. Put on my spare used starter and housing- and it worked. no more problems maybe u can find a junk yard starter and see if it fixes your issue as well

sam333

There are other threads here on this topic. Check all heavy wires off the battery, grounds and power.