Another S13 Alternator issue, maybe regulator

[Cgeigert]

I've had quite a bit of experience with the alternator in my car, you can peruse my previous threads to see. This is for s13 with sr20det but it's probably similar to KA. First thing I've learned is that the alternators seem to go slow in these cars, rather than just crapping out all of a sudden and then the car dies with no power at all. I already replaced my alt. recently with another used one and I think this one is starting to go now. Car just started losing power under hard throttle so I babied it home and checked volts, they were dropping under 12 and alt. was only putting out around 11.5. So I charged the battery and drove it around it and it was fine but when I checked volts it was around 19. Turned the car off and tried again this morning and volts were at around 16 stable, with one jump up to 19 for a few seconds. While the volts jump up and down around 16 the idles gets faster and slower. So it sounds like the regulator right? Probably just gonna throw a KA alt in now.

[ricebike]

So it sounds like the regulator right?

yea, shouldn't it only supposed to go up to ~14.5V when charging?

doesn't hurt to bring that removed alternator to have it "bench tested" for free at the local autozone/ advance auto parts/ whatever auto parts store nearby to confirm

[Cgeigert]

It's still running way too high so just gonna swap out for Ka alt. Trying to get one off eay so I don't have to pay a core charge but can't confirm correct part number.

[Cgeigert]

Anybody ever used the Hitachi 15937 ? It's supposed to be a direct KA replacement with 90 amp.

[ricebike]

i thought you already had a replacement alternator on standby...

i got a duralast replacement with a lifetime warranty from autozone...$$$
it's rated to 80 amps only though...

with all that overcharging, expect to get a new battery or at the least check the fluid level so you won't dry it out

[OutToWinPAHC]

A bad battery can work the hell out of an alt.... to death

[Cgeigert]

I had the replacement s14 sr20 alt I put in a couple months back but that was a used one and now it's overcharging at 16amp. Battery is less than one year old. I have another spare used s13 sr20 alt but that is testing bad so I'm gonna just do the KA one. I tried to get a bosch one at pep boys but we couldn't get the pulley off the new one so I have to get it at another store. I'm not surprised the old used alts burn out, no stereo but about 10 pounds boost and silvia lights. I believe there is a s14 ka24de w/ foglights alt that does 90amps but I'll see when I go back to the auto shop.

[Cgeigert]

Got a rebuilt OEM KA alt at napa for $150 and it's in now. Drilling out one hole took two seconds. I didn't realize the pulley would scrape so I used a very thin spacer under the sr pulley, it's just a hair off but works fine. WIsh I had done this the first time around instead of using a used sr one.

[asoomal]

Overcharging at 16A or 16V? If it's volts, check your battery. Low electrolyte levels will cause high voltage.

[Cgeigert]

Overcharging at 16A or 16V? If it's volts, check your battery. Low electrolyte levels will cause high voltage.

I meant 16V. All my issues have been alt related, both my s13 have new batteries within the last year.