crashburnoveride

Thought I'd see what you guys recommend. I got in my truck this morning and the charge battery light was on. My turn signals weren't working or my led lights I installed under the dash. I figured it was just a blown fuse so I drove it. Ran fine. Tonight in -15 wind chill it started right up. CHarge light still on. About 10 blocks from work I started to lose power. Couldn't accelerate. I turned off the heat (which was blowing slower than normal) and got a little power back. Then she just died. Got a tow to work. Let it sit in the parking lot for 2 hours. Then it started up again and i drove it some in the lot. What gives!? Alternator? An electrical short? I may just have it towed to a shop abd checked over. Whatta yuh think?

Terrys87

iTrader: (1)

With it idling, put a volt meter on the battery. You should have 14 volts, that should tell you if your alternator is going out. If less then 14 volts, most likely a bad alternator.

rattlewagon

^ This. Go at it with a volt meter. If you dont have one, most auto zones (or similar stores) will test your batter for free.

crashburnoveride

If it is the alternator didnt I see some sort of chevy alternator swap? I think it was chevy... been a while since ive been on YT. Do our stock ones suck or what?

CJM

soon as that battery light kicks on 9x out of 10x its the alternator not charging and going bad. Buy a new alternator and abattery, you more than likely cooked the battery as well since the truck had nothing to run on. Dont play around and just replace the alt, seen the battery go south many a time after this situation happens..

Gevo

Yah. Alternator. Also. Why do you want a chevy swap? How long did your alt run for?

RJR

I agree it's probably the alternator, given that the light was on (a voltmeter will tell you for sure, as has been mentioned). When the alternator stops charging, the battery will heroically supply juice to run the engine ECU, etc., until it runs down, at which time your engine starts missing and then stops. Letting things sit sit for a while usually allows the battery to regroup a bit, so it may run again for a while. I don't know at what voltage the ECU shuts down, but given that the truck started 2 hours later, the battery probably wasn't that far run down when the ECU quit.

I disagree that you probably cooked the battery. No particular reason it should happen just because the alternator isn't charging. You've done less harm to the battery than if you'd left the headlights on for 4 hours or so.

The alternator can damage a battery if it is over-charging it, but lack of charging typically just runs it down without damage.

However, if the battery is more than 3-4 years old, all bets are off. I've seen lots of weird behavior that looked like alternator problems but turned out to be a worn-out battery. When they get old, cells start intermittently shorting out, causing erratic behavior.

Sturmcrow

My understanding is that alternator swaps are done to increase the current delivered. Our stock alternator is only 60 Amps (so 720 Watts, or so). Considering that I am pulling 360 Watts, just from having my high beams on, it can make sense to upgrade to a bigger alternator.

For those that think I may be pulling the 360 W from my posterior, I am adding up the two 100W high beam filaments, plus the two 80W low beam filaments that come on since I wired the headlights up myself and have not bothered to figure out how to isolate the low beams from the high beams.

Gevo

I wonder what difference those who have swapped the alternator are noticing in the light performance. I ask because I see everything fluttering just a little when any electrical item is used. Flashers, windows, headlights.. etc...

I fear the wiring is going to end up being the choke point.. But, I will read up on this in the future.. i hate the fluttering lights.

toy89yota

The only time I have ever seen my battery light come one was when my alternator gave up the ghost. Acted just like you described, smoked my battery in the process.

donomite49

Alternator brushes - cheap easy fix.

toyospearo

x2

RAD4Runner

O.P.
What model -year do you have?

Did you check the fuses before entrusting your baby to others? Oh No! most especially the engine fuse?
Does your back-up light work?
Where did you connect your LED light?

If you have 22R-E, back=up lights, turn signals and the excitation supply for your alternator comes from engine fuse. See schematic below.

Engine fuse also sends signal to ECU See below.

AMEN! Check and verify what's really broken. Next to our senses (FREE), the multi-meter (inexpensive) is the best diagnostic tool for our trucks

No, our stock alternator do not suck. However, IF one adds auxiliary circuits that put more demands on the stock alternator, then he would need a higher-capacity alternator; 4Runners absolutely do not suck. However, for towing a trailer with a 30-foot sailboat, you'd have to upgrade to Lancruiser .

A swap is OK if needed. However, take it one step at a time. You don't want to add variables to your problem.

Agree... but re-phrasing... "not charging and/OR going bad."

Yes and no. Could be the alternator but it may also be because it's not getting "IG" supply from Engine fuse; like we may have good soldiers but they could not fight well if Pentagon does not supply them with enough ammo and supplies

Dis-agree. Don't condemn the alternator. Innocent until proven guilty.

May work on others, but PLEASE do play around; Poke around with your multi-meter. See my sig for charging system explained.

Check and verify what's really broken before spending hard-earned money replacing parts that are not broken. Our senses are free, the multi-meter is inexpensive.

In the process, you would understand our trucks better and you would not be dependent on Stealership who charge you for their guesses - right or wrong.

Agree.

Agree. You'd be lucky if battery lasts 5 years.