what kind of alternator for 1991?

[viracocha]

I was hoping for some help identifying what kind of alternator to replace my existing one. I went to a parts store and had them test because of intermittent starting issues. Their machine's results were that the voltage regulator and diodes(? i could be wrong with this name) were bad/malfunctioning. They looked up information in their system and said that the voltage regulator was external. I held off on ordering anything to do some research, because I remember reading bad things with some aftermarket parts.

According to my manual, the voltage regulator is internal and it seems that is the case when searching on here. But, when searching on here, it seems that it could still be 80 or 90 amp depending on if the fan is internal/external. Does this mean external to the housing? I've been trying to find pictures of either for comparison, but haven't had any luck. I think what I have is the 80, but I'm embarrassed to say that, initially, I think I've was looking at the wrong part, so was wondering if anybody could confirm.

The starting has degraded over the past few months to the point where this weekend, it wouldn't turn over without my portable jump starter.

If I can figure out if it's, 80 or 90, I was going to quickly order a replacement and try to install it myself. I've been looking at general auto replacement videos, but haven't found any specific write-ups or videos. Sorry if this is a dumb post, obviously I'm a super newbie with this stuff.

 

[jonheld]

You have an 80 amp alternator, external fan, internal VR, non-rebuildable.
Pick up an OEM remanufactured unit from one of the many vendors on this forum. You can get an aftermarket unit, but you'll be replacing it in another 6 months.

 

[Aggiesdm]

That picture is of an 80amp alternator. Probably stock on your '91. External fan is the give-away. There are aftermarkets available, but they have mixed reviews on reliability. They aren't easily serviceable either and many alternator shops want to charge as much as a new (refurbished unit) would be just to replace the brushes and get it working again. Your options are:

1. Buy new (refurb unit) Toyota unit
2. Pay handsomely for a rebuild
3. Try and aftermarket from auto store
4. Find a bracket, alter it to fit and put a 90amp unit in (search MUD for info on this)
5. Find a OEM replacement from a junkyard (thats what I did). Check out www.car-part.com

I found an parts truck at a junk yard that had 140K on the odometer and bought the alternator for $25. Took it to Autozone of them to test it before I installed it. All good. Dropped right in with no problem. Been over a year now and its still doing fine.

Good luck

 

[LS1FJ40]

You have an 80 amp alternator, external fan, internal VR, non-rebuildable.
Pick up an OEM remanufactured unit from one of the many vendors on this forum. You can get an aftermarket unit, but you'll be replacing it in another 6 months.

X100 on buying an OEM reman unit. I tried to save a few bucks 6 years ago and replaced my alternator with one from OReillys. It was dead in the box. Uninstalled it and exchanged it. The replacement lasted 3 weeks. Ordered an OEM reman and took the other back to OReillys.

I would love to figure out a way to do a Tundra alternator (or similar 140+/- amp) on the 3FE. I'm sure it's feasible. It's gotta be!

 

[Alleycats]

Someone was saying that when you buy a remanufactured alt. or starter from Toyota you occasionally get a new one, just throwing it out there.

 

[LS1FJ40]

Someone was saying that when you buy a remanufactured alt. or starter from Toyota you occasionally get a new one, just throwing it out there.

Yep. A lot of the Toyota Reman products are that way.

And if you order Aisin parts sometimes you Toyota parts with the Toyota grinder off.

 

[Tools R Us]

You have an 80 amp alternator, external fan, internal VR, non-rebuildable.
Pick up an OEM remanufactured unit ....

So, that is kinda confusing, if it's "non-rebuildable" how would you get a "remanufactured unit"?

The DENSO Part # 2100105 is commonly available, http://www.rockauto.com/ has it for $101.99, with a $34 core.

 

[jonheld]

So, that is kinda confusing, if it's "non-rebuildable" how would you get a "remanufactured unit"?

The DENSO Part # 2100105 is commonly available, http://www.rockauto.com/ has it for $101.99, with a $34 core.

Technically anything is rebuildable with the proper equipment, time, and supplies. The 80 amp Denso unit is a royal pain in the ass to rebuild and the rebuild parts are more expensive than a remanufactured unit from Toyota. I had my old one apart on a workbench once and tried to get the main board out so I could get to the brushes. Diminishing returns. IMO, not rebuildable or at least not worth the effort.
I'm sure Toyota sends these out to a certified Denso rebuild shop to have them "freshened up".

 

[DieselDriver]

I have a new (2 months old) reman from my local parts store
I'll sell cheap if your intrested?

 

[landcrshr]

Their machine's results were that the voltage regulator and diodes were bad/malfunctioning. They looked up information in their system and said that the voltage regulator was external.

Speaking of contradictions...

 

[viracocha]

Thanks a bunch everyone. I definitely appreciate the help. I re-read the electrical systems section in the manual and with your feedback in mind and things make more sense.

I kind of re-evaluated things. When I turn the ignition to the on position, everything seems pretty normal (radio, lights, etc). I checked the voltage of the battery with everything off and it was 12.6. When I try to start it, initially it just makes the click sound. This morning, I didn't connect the jump starter right away. After about the 5th or 6th turn (without the jump starter), it made a sound like it was actually trying to turn over for about 4 seconds and then started. I wonder if it was just a coincidence that it started when I connected the jump starter the first time.

After reading a bunch of posts here, the symptoms (click sound, eventual start) seem very similar to those that ultimately had ignition switch issues? If it was the alternator, wouldn't I end up with a dead battery at some point? Maybe, I should take it back to the auto parts shop for a re-test, but I was thinking of trying to replace the ignition switch and starter first.

 

[Alleycats]

Dumb question, but you ruled out a bad battery?

Also when my alternator went bad the dash lighted up like a christmas tree while still running.

 

[viracocha]

Dumb question, but you ruled out a bad battery?

Also when my alternator went bad the dash lighted up like a christmas tree while still running.

No question is dumb when it comes to me and autos! The last check at the auto parts store showed the battery was still good, but that was 4-5 months ago. Maybe something has changed because of my procrastination. Good to know about the dash lights, though. My lights all go away after it finally starts. I'm going to run out quick to get it tested again.

 

[PLATX]

I got a custom build with the 80 amp body but 140 amp guts out of California for about 150.

 

[jonheld]

I got a custom build with the 80 amp body but 140 amp guts out of California for about 150.

Are you certain it is an 80 amp OEM unit with the external fan? I ask because I have had several shops tell me this can be done, but they're talking about the 90 amp unit with the internal fan.

 

[sbman]

If you have a voltmeter it's easy to check the proper functioning of your alternator and battery.

Test the voltage of the battery with your voltmeter with the leads directly on the lead terminals, not on the truck's battery cables. If you are measuring 12-12.6 at that point it sounds pretty good. Now get someone to try to start the truck while you continue measuring the voltage. If the voltage suddenly drops to 10 or lower and nothing much happens with the truck (slow or no cranking) then you've got a dead battery that needs charging. Charge the battery with a charger and re-test. If you get the same results after charging, you have a bad battery.

If the voltage remains at about the same level when you attempt to start the truck @ 12+ volts, and you get no cranking or just clicking, you have some kind of wiring or starter issue because the power isn't reaching the starter or the starter isn't engaging it's solenoid. Clean the terminals with a battery brush and water, re-assemble and re-test. If you get the same result, you probably have a bad starter or starter relay, or a blown fuse some where and you'll have to fix the starter problem.

Once you have the truck started with the above diagnosis, you can check the alternator function. While the truck is running, the voltage at the battery should be 13.6+ volts. It should not be higher than 14.8, if it is 15 volts or above, shut the truck off immediately and replace the alternator because it's regulator has gone bad and damage can result from over-voltage. If the voltage stays at 12 volts or so, the alternator isn't charging the battery and needs to be replaced.

With experience and regular (non HID, non LED) headlights, all of the above can be verified using the brightness of the headlights.

 

[viracocha]

Had a new baby to deal with, so was away for a bit.

Thanks for the great writeup, sbman. It was easy to follow. The voltage was 12.4 cold and when trying to start, it ranged from: 11.5-11.7. I know you said below 10, but after a bunch of fiddle-faddle and my lack of experience, I just said "eff it" and replaced the battery. First three turns resulted in the single click. Then the fourth turn, it wailed slowly, turned over and then stalled out. Fifth resulted in the same. Sixth slowly wailed and then it actually started. The sound was kind of unsettling. I've never heard my engine make that sound. Kind of like it could stall out an any moment. I let it run a bit, then drove it around and it returned to it's normal sound. Ever since then, it fires up instantly and the gurgle sound hasn't returned. 3 days of driving and everything is happy.

Well...I'm an idiot. Dumb internet has turned me into neurotic hypochondriac on so many levels. /sigh yet another instance where I turned something that should've been simple into a complex mess. The battery was old enough to need replacing, should've known. In my defense, before replacing the battery, I took my cruiser to auto parts store for testing and, although it had intermittent issues starting, their device reported the battery, starter and alternator were all good.

Oh well...I learned a bunch. I had a lot of trouble identifying the starter (actually, I'm still not 100% I've identified it).

 

[viracocha]

Well...if it quacks like a duck, it might be a fricken platypus.

After 3 and a half days of starting awesomeness, I almost got stuck in a parking garage. This time, no slow degradation, it was instant. I re-tested voltage, 12.5 when cold. 12+ when cranking. I disconnected/reconnected battery cables just to check, no help. I noticed that the key column was replaced when I bought it. Maybe related to ignition switch issue?

Checked fuses. They look good. Not sure what to look for with relays and fuseable links.

Has anyone found where to get a good manual for a 3FE? Mine is from 86-95. Some of the diagrams are missing for my year I think (where the starter is, solenoid).

 

[jonheld]

Has anyone found where to get a good manual for a 3FE? Mine is from 86-95. Some of the diagrams are missing for my year I think (where the starter is, solenoid).

in my signature line

 

[jhunhapi]

Kinna off topic. Is possible to install 130/150 amp from Tundra/Sequoa alternator? Some done it before. Like others made for FZJ and just changing the brackets but Photoman stop making the brackets for them. Or just stick with the 80 amp Denso?