Yesterday the Runner started acting up, thought it might be an electrical problem.... Checked the search bar, but couldn't find anything specific enough...

When engine is above 3,000 RPM the battery charge and brake light come on, when I shift and RPM's go down the lights go off. Checked alternator belt for tension and seems good.

 

Fastest way to check alternator, start it up, keep it running, and disconnect the negative cable from the battery, while the truck is running. If the truck dies, the alternator is not charging. If the truck stays running, more than likely a battery(#2 option) or wiring issue(but not highly likely).

Or you could just replace everything in the charging/starting system. Hopefully the problem is in that list somewhere...

 

It is most likely the brushes in the alternator are worn, easy cheap fix.

http://www.4x4wire.com/toyota/mainte...nator_brushes/

Just pop the back off and take a look, if they are worn replace them but DO NOT GET A AFTERMARKET REMAN. Get the parts from toyota for less than $15.

 

^^^ This.

 

My 4Runner did that to me when I first got it. I put a new alternator on it and the lights never came back on.

 

Same here. 85 p/u. Alternator was culprit. Lights went out.

 

Hey, this is currently happening to me too!
When the RPMs are at 3,000 & up the brake & batt light come on then fade away. But, i think for me, this is due to my busted alternator bracket. It lets the belt flex & have too much play slipping on the pulley.

So, check your bracket!

 

it happen to me 2 week ago, its the brushes as mention above. just get a new alternator. thats what i did and drove it 3 hrs straight right after it and drove it all this week.. no more lights flickering... done..

 

Don't get a reman alternator...rebuild oem. Brushes are cheap.

 

these alternators are bulletproof minus the brushes that wear normally.the advise to rebuild yourself as always a good choice,considering the "rebuilt" alternators are often worn out and simply patched up and painted pretty for resale.if you must buy a rebuilt,be sure to get a denso genuine rebuilt for a few extra bucks.

 

i'm posting here, as well as a new thread, to ask for some insight...

this is a case of the charge light not coming on. at all. all connections seem fine, alternator output is good with no issues, the bulb is fine. the truck starts and drives fine, but the charge light never comes on. my alternator swap did not cause this, as i've driven with it for a year, issue-free.

my setup:
-cs130 140amp gm alternator
-plug and play adapter

i know the light is supposed to come on. this was taken a year or so ago:


so, anyone got any ideas?

 

Had the same exact problem with mine today after mud boggin, and just pressure washed the motor, and still it was happening, hit it the alternator with a wrench a couple times and sprayed the plug with electronic cleaner, works fine now all the lights went away and volts went back up to normal.. my guess was some mud in the alternator somewhere?? Im not too sure, just know my yotas working fine now

 

Irab88, I know it is a little late, but you might want to check the cluster. The copper on the back may have corrosion or a break in it not allowing your charge light to come on.

 

I spoke too soon x.X problem came back after a hour, so im guessing it could be something with the wiring plug, or I might have gotten a lil too much water in the alternator.. might need to rebuild.. ill post here if I figure something out

 

So I was driving down the road, and the truck started sputtering, and didn't want to move, then completely died, battery volt level showed approx. 9 volts if not less.. and the alternator was done! I did a side of the road alternator and battery removal, walked my happy ass to autozone (luckily it was about 1/2 mile down the road) and got a ride back to my truck from a buddy, (only spent 45$ for the alternator and battery was free under warranty) put everything back together, and problem was gone, everything works fine. I don't think ill be mud boggin that hard again real soon.. but then again free replacement alts for life and it only takes about 15 minutes
Moral of the story.. break down and spend the money on the alternator, before it leaves you stranded somewhere with no car parts store in sight..

 

I would never buy a remanufactured alternator, especially from Autozone. 90% of the time you can rebuild OEM for $15-20 and it will be way more reliable. Hopefully you didn't give them your stock alt as a core.

 

Nope, I have the stock one and im going to rebuild it, and either put it back in the truck, and save the autozone one for a spare, or leave the autozone one in until it goes and then get a free replacement, and put the oem one back, but that's why it only cost me 45$ I just paid the core charge, so I could get one that works, and save my oem one

 

I recently had to replace my alternator after buying my truck and driving it around for 1000~ miles or so. Previous owner had let it become caked down with sludge and mud.. so I bought a reman'd Denso one. The old one has an autozone POS.
I buy a can of electric parts cleaner spray and spray it on my alternator and other electronics after each wheeling trip just as a cheap insurance.

 

coat plug terminals with dielectric grease and you don't have to worry about water.

 

similar unsolved problem.mine is a 1987 charge and brake lights stay ON.So I replaced the alternator with a brand new alternator, not rebuilt. same thing lights stay on... then I checked the output of the new alternator 13-14 volts.. replaced all belts. replaced the battery, stll lights stay on. checked the fluid level and float switch on the brake resv., al OK. Checked the wiring harness and plug to the alternator, all clean, sprayed with CRC contact cleaner,lights are still ON, I say: the CHARGE and BRAKE lights are on at 1,000 rpm, or 3000rpm. the lights are ON what's next ?????