Pulling my hair out over a charging issue on a 97 tacoma

If anyone has any insights or experiences here to help me out I would DEEPLY APPRECIATE IT. At the moment this thing has built me up to break me down so many times I'm ready to drive it into a lake. Here's the long and short of it:

Couple weeks ago my battery light started coming on intermittently for a few minutes while driving. Typically it would come on shortly after starting the vehicle, and go off not long after. After a while it started coming on more frequently, until eventually it would come on and seem to stay on. I figured it couldn't be too complicated, so I tried a few things.

Checked the connections on the battery terminals and alternator for corrosion, and cleaned them anyway even though they seemed fine. It worked!.... until the next time I started my truck a few hours later.

Noticed the ground clamp on the battery terminal was cracked and loose, so I replaced it with a new clamp and shimmed it up good. It worked!... until the next time I started my truck a few hours later.

Took it in to Advanced Auto and had them hook it up to their machine to see if my alternator was going out, and here's where things started to get murky. The initial test read ZERO CHARGE from the alternator to battery (while the battery light was on), but the next test turned out fine. Everything seemed to be working alright. The guy who ran the test seemed a bit puzzled.

I pulled the alternator out of the truck and brought it in for a proper bench test. It passed the first one. They ran it again, and it failed the second test. Something about a bad circuit. AH HA. THANK GOD, I thought. Bought a re manufactured Car Quest alternator (thinking maybe this is where I went wrong) from them for 130 bucks or so (with core charge), threw it in, and it worked!... until the next time I started my truck a few hours later.

Brought it back to Advanced Auto with the battery light on, and again it read NO CHARGE to the battery. The guy suggested that maybe the alternator to battery cable was bad, so I threw on a 5 dollar jumper on top of the old from alternator to battery. Also pulled off a bunch of after market crap that was attached to the positive terminal, and replaced the alternator fuse for good measure. Turned it on to run the test and it worked perfectly again!.... until the next time I started my truck a few hours later.

As of now I have an appointment to have my favorite mechanic take a look at it next week, but I was wondering if anyone had any clue what else might be going on here? I feel like if the light was on from a small power drain the test would not read NO CHARGE coming from the alternator. So far the truck hasn't died on me, it has so far worked enough to keep the battery charged here and there, just not regularly. According to the test the battery is good. The alternator is new. There is a new cable going from the alternator to the battery. My only thought at this point is that maybe the old bad cable somehow is shorting out to a ground cable in the same wiring harness and dumping the whole works?

I also took a look at the block ground and it looked fine, though the engine side was covered in old oil.

What are the odds that a remanufactured alternator would have the exact same problem as the one I pulled out?

Lord have mercy. Any other tips? Ideas? Miracles? I am near my limit in shattered dreams.

 

Alternator went bad and took out the battery. You also may have a parasitic draw.

 

This seems like the simplest and most logical solution, but the guy at Advanced Auto assured me and reassured me that the battery was fine, and talked me out of getting a new battery, based on the test. "It would have a whole different set of numbers if the battery was bad." But I have a feeling he doesn't really know what he's talking about. Is the ability to charge separate from the ability to hold a charge in the battery? When it does charge it charges right up to where it's supposed to.

 

Take it to an electrical shop that specializes in rebuilding alternators and starters.

 

I live in BFE, I don't think we have such specialists around here. Something I just thought of if it makes any difference regarding the battery potentially being bad: all this started after it warmed up 40 degrees overnight after a week of subzero temperatures.

 

This thread is very anticlimactic

 

Story of my life!

 

is the battery light still coming on?

 

Yeah, it's been on since I left work (it was OK on my lunch break right after jumpering the alternator to the battery). Swapped the alternator fuse (nice 1 hour job in the parking lot thanks to an invisible BOLT holding it in) but it didn't help. Light is on, test showing NO CHARGE.

Thinking about just buying a spare battery and a charger and going with it.

 

I see there's another wire that plugs into the alternator with a special electrical type connector. I'm assuming that's the line that feeds it power. I wonder if that wire is shot, if the alternator wouldn't charge

 

If there is no charge there is a problem with the alt!
get a oem toyota alt.ive never had any luck with rebuilds from auto part stores.
just my opinion

 

You're probably right, but having the exact same issue with a different but new alternator is a hard mountain for my troubleshooting brain to get over. The odds just seem so unlikely! But there it is- the most obvious solution. Maybe I'll put it out and go have them bench test the new one a few times at the very least.

 

thats a good idea, but if it isn't making voltage in the truck, it's not going to on the bench.

 

If it confirms that the new alternator is as bad as my old one I'll weep for joy at having found the problem (again).

 

Are there any codes at all?

Try a different known good battery.

Try another place to test the system other than AutoZone.

I have been through some of this on one of my previous Toyota trucks. Bad alternator. Replaced alternator, but didn't realize the plug wasn't in all the way, which stranded me in the middle of a busy main street. Managed to get it to a shop where it was fixed for free. Battery died soon after. I kept having issues and it was a loose clamp.

So check ALL the connections and plugs and clamps you can find / reach. Try a different place for testing the alternator.

Hope you can find the problem. Normally, the stock charging system is reliable.

 

Clueless on what BFE is.

But you don't think there are any, but you don't know. Many times they are small shops in out of the way places.

It's worth the effort to find one.

 

BFE Big F*****g Empty. Middle of nowhere.

 

BFE is local slang for middle of nowhere. You’re right it’s worth looking and I’ll check all my resources tomorrow.

 

Haven't checked the codes.

Good idea to have it checked elsewhere. I only go there because both the alternator bench and the in vehicle test machines are free. I know of one other place but it's like 10 bucks and is probably the same machine. I'll check around for other places while I'm looking for possible electrical specialists.

I went clamp/connection crazy as one of my first attempts at fixing it. I've had the same issue you've had in previous vehicles because of loose clamps, so that was my initial assumption.

 

Some great, talented, intelligent people work in all fields and levels of automotive care...but in college I worked for both AutoZone and advance. Typically each store has a "parts pro" other than that your typical counter worker is as untrained as it gets. Sure you find some skilled hoppyists, enthusiasts, and retired techs and mechanics. But the basic counter person, received little to no training. Electrical shops, generator/alternator shops, and most reputable repair shops are far superior for stuff like this.