Inconsistent Charging.

[Esenpai]

Alright.

So over the last 5 months or so...or whenever 86fest was(alternator died on arrival) I've been having alternator problems...well actually after 86fest there wasnt any problems until a few weeks ago when my alternator died(alt that I replaced at 86fest with a refurb from pepboys)
I was driving to get dinner on a friday night noticed my digi dash started to flicker and fade. my lights began to dim yada yada I'm sure you know how it goes. so I ended up getting home with the help of a friend giving me a could charges(luckily I have a nice yellow top optima battery which made it possible to get home 35ish miles on a 30 min charge)

Got it home tested it alternator wasnt charging. so got another from pepboys. did some research and decided to go with a 91 corolla gts with 4ag alternator since its outputs a bit more amps...(70amps over our normal 60.) figured it wouldnt be a problem with it being the same engine should be able to handle the revs and what not. first one was bad.. caused a lot of popping thru my speakers and I could literally hear the alternator turning when I was looking at it in the engine bay. which isnt something I've ever been able to hear it sounded unbalanced. it also didnt keep a consistent voltage so I called PB and ordered a replacement. went to go pick it up smartass kid that worked there was like "that just sounds just like a grounding problem but okay I need to test it anyways company policy" yada yada just based off the fact that there was popping thru my speakers(which could be correct if the rest of the problems werent present) well he was wrong and wouldnt even show me the test results because they were bad obviously. then he proceeded to tell me they didnt have my replacement I ordered I told him to go check the will call he did and WOW my alternator was there.
okay I'm going to stop with my rage story and get to the point.

new alternator got it. dropped it in. worked fine in the garage tested at about 14.2v at a 900rpm idle. then while driving charge light came on.(sometimes it will even turn off for a while then come back on) got it home it read 12v and was slowly dropping at first. now heres what weird. if I let it just run. it will slowly climb in volts. up to about 12.7-13v depending on the day. sometime it will work fine for a while then randomly the charge light will pop on. I've also noticed that it will happen after I down shift sometimes (may be unrelated but worth a mention) also if I rev it up real quick while idling it will go up to about 13.4 vand then if I give it a few more revs it will drop back down to >12v then slowly climb back up. it is just another bad alternator I checked all the wires and ground locations I know of and can see in the charging circuit itself. all seem good and connected. no blown fuses or anything. I have about .4 ohm in the positive cable coming from the alternator to the battery. I'm pretty stumped as of right now other then getting another alternator and hoping its actually a good one I dont know what else to do the cable to the positive post on the alt is starting to look pretty ugly. so maybe I should replace that one? ¯\_(ツ)_/¯

any input would be greatly appreciated.

thanks guys

[gotzoom?]

Check the round connector on the back of the alternator. If it isn't snapped in all the way, you'll get random charging. You may need to unplug it and clean the contacts too. Mine was all gunked up with oil and when I cleaned it, I haven't had any other problems.

[Esenpai]

Check the round connector on the back of the alternator. If it isn't snapped in all the way, you'll get random charging. You may need to unplug it and clean the contacts too. Mine was all gunked up with oil and when I cleaned it, I haven't had any other problems.

its def plugged in checked and recheck that several times I'll try cleaning it out a bit. see if it helps.

EDIT: checked the plug its super clean not dirty at all. voltage will drop is I jiggle the plug really hard but doesnt happen ever time I can be jiggling it and nothing will change. so... still no idea.

[totta crolla]

Just to confirm, you definately have a good ground between the engine and body ?
The engine ground wire should be about the same diameter as the battery ground.

[midwest86]

I fought similar problems with those cheap Chinese "rebuilds" from parts stores. I spent 3 weeks of misery testing every wire, connection, and ground before buying an OEM Toyota alternator. Slapped that baby on and haven't had a lick of problems since. Pony up the cash and buy a quality part.

[mad_86]

Check your battery terminals also so I seen a few beat up
Terminal don't get good connection .
Also check battery
If it's been more than 4years of daily driving battery just may
Be on it's way out ... Even if it's a optima...

[warnarf]

My fix for this problem was replacement of the round plug's pigtail. If you unhook your plug, you'll notice the wires will have naturally bent downwards due to gravity and if you bend them the opposite direction I bet you'll find the insulation and wires are broken. This is why it drops out when you wiggle it. The plug can be bought on Amazon, Rockauto, and Ebay for about $15USD.

[Esenpai]

Thanks for any of the input. Car was totaled over the weekend. The dream is over for awhile . (｡•́︿•̀｡)

[mad_86]

Man sucks to hear that man.. Your black hatch
was pretty clean..

Your interior for sale??

[Esenpai]

Im going to hold onto it for now. Since its all pretty decent and if i gt-s swap a sr5 i'll need it