3fe 90 amp alternator? (1 Viewer)

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Nov 23, 2005
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Birmingham, AL
 
 
My alternator went out a few months ago and I am finally getting ready to get working on it. I have researched the differences in 80 and 90 amp alternators for the 3fe and can't find a clear method for Identifying the difference. One post says the 80 amp has an external fan and I have read elsewhere that the large threaded stud is on the side of the 90 amp. I am skeptical that I do in fact have the 90 amp, although it looks like I might. So, can anyone help me figure out which alternator I actually have?

**update** - it was an 80 amp with all the characteristics of a 90 amp. I bought and modded an actual 90 amp to fit, details in post 10 **

alternator1.jpg

alternator2.jpg
alternator1.jpg
alternator2.jpg
 
Last edited:

Lka1988

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Looks like you got the 90A unit. It has an internal fan and the stud on the side, while the 80A (more common) has the stud on the back and an external fan.

Lucky :flipoff2:
 
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are there any good upgrades to a more powerful alt for the 3FE. I've read lots of threads on up grades to the 1FZ but not the 3FE
 
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NE Ia.
 
 
3FE Alt. Problem - Bumped

Bump'n up on a 3FE Alt. problem & gen. question on my 92.
Had the 80 Amp. ext. fan, DENCO (something like that) that
diodes were shot and ran into the ground. So, the CHEAP A**
I am, went to O'Rielly last Dec. and bought a reman. 80 amp.

Nothing but problems, works fine on trips, yet back to in-town &
stop/go driving, you see the alt. guage drop from near 3/4 to just
above mid. range on guage, then add night driving, etc.
Get ready to grab the jumper's.
Even the power windows, hit 2, and the guage just dives down
about 3 needle widths. Below 0 weather, forget it, it just would
not charge system.

So, spring sprung, complained and got another, and ran hours
tonight. It's NO better. They were suppose to swap me for a 90
and I'd pay diff., yet ended up w/ another 80 amp., so figured to
try it. Same low output, havn't checked w/ Volt reader, just exp.
running around / short trips / Alt. Guage.

Any suggestions?? I'd like a 90 amp. (DENCO again ?), or Cdan for
a Toyota OEM ?? I'd like to add some lights and another bat., yet
if Alt. won't charge system, don't need more ??'s in the Elect.

At moment, seams like a pricey core to go elsewhere, yet seams
to be the right option. Confirmation of my stupidity appreciated!

Later....:hmm:
 

Land Speeder

InstaH8R
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Matt, Call your yota parts counter, I'm pretty sure they list both, but can only get one, the one you need. I have no idea why they list one that they've never sold in the US. It's only a 91-92 hiccup though.
 
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TX
Yep that's the 90A.


hvymtlfan...

Until recently, I've had Bosch reman'd alts (80A) and encountered similar issues with the electrical system showing a pronounced strain on the voltmeter when using p/w or blinkers etc...

So instead of replacing the Bosch, I opted to spend the cash and get the factory Denso unit from Mr T.
No change...same funky electricals. Everything works, and it does charge properly but I was hoping that the denso unit would cure the dimming lights when I use the turn signals at night.

The fusible links to the batt have all been replaced within the past 2 years, so they are still like new.

Anyone with a 3FE and 80 amp alternator, that does not have this electrical system quirks?
 
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Central NJ
I have a Denso 80 and have the same issues. I have a digital volt meter in mine and it typically drops to 12.1-12.4 night time. On a rainy night, engine hot, wipers on, headlights on, heat on, stopped at a light, it could dip into 11.6-11.7 territory. At startup, high idle, it charges as it should at 14.2-14.4


Since it charges fine even with a wimpy 80 amps, the problem seems to be that the alternator spins too slowly at hot idle. To cure this easily, I thought about replacing the alternator pulley with a smaller diameter one. That way, at the same engine idle, the alternator itself would spin quicker. I havent looked into it but Im sure any alternator shop could source such a pulley.
 
Joined
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Yep that's the 90A.
actually, it was an aftermarket 80 amp with all the characteristics of a 90 amp. I ordered a replacement toyota 90 amp and there were some differences, but I was able to make it fit by grinding one of the mounting arms a little bit and enlarging the hole on the power lead. I have been waiting to do a write up until I had driven it for a few weeks to make sure everything is working, but it seems to be working fine.
 
Joined
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Here are the two alternators side by side, the 90 amp is on the right. The two mounting tabs on the bottom of the 90 amp are closer together than the two on the 80 amp. The tab for the adjustment arm is larger too but that didn't cause any problems.

img152.jpg

This is what I took off with the grinder to make it fit. the upper tab in the picture had the same profile as the lower tab originally I taped over all of the openings in the alt. first and cleaned everything up before taking the tape off.

img154.jpg

this is a little art project I made to try and explain why it wouldn't fit and how the grinder helped. the red lines are the tabs on the alternator and the blue is the mounting point on the engine. Front of the truck would be to the left.

altbracket.jpg

without the tab on the back of the mount I had to reverse the direction of the bolt so the nut was in the back or else the bolt would rub on the belt. It was a little difficult to get in in backwards with everything lined up, but I threaded the mounting bolt for the air pump in forward to get everything lined up and pushed it out backwards with the alt bolt. the bolt for the power cable was 12 mm instead of 10 as well so that had to be drilled out and I added a larger nut. I had some more pictures of it installed but left my old digital camera on the bumper when I took it for a test drive. I'll try to snap one with my phone camera later today.
img152.jpg
img154.jpg
altbracket.jpg
 
Joined
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Wichita, KS.
I bought a remaned denso I believe from a fellow mudder when my original went at about 189,000 miles. It also does the slight drop thing when the lights and blinkers are on. I always drive with my lights on, probably cuts down on alternator life, but I figure I'm more visible that way and any accident is sure to total me. :) I have heard that the 1HZ alts. fit the 3FE, but thats pure hearsay.
 

Moby

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Trying to stack dimes
 
 
 
are there any good upgrades to a more powerful alt for the 3FE. I've read lots of threads on up grades to the 1FZ but not the 3FE
Mean Green makes one. 140 amps I believe. I've heard mixed results.

I have a custom 175 amp unit that Northwest/Wrangler Power Products made for me using a new OEM 80 amp case. ~12,000 miles and going strong. This was not cheap but I run a Ford Contour electric fan along with other extra electrical accessories.

I also had a Mechanical Man 175 amp unit that used a Ford case with adapters for the 3FE. Ran this for a while but eventually I got frustrated with the adapters and keeping the belts aligned and went to the NW Power Products alt.
 
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I also have these weird electrical quirks as well. I've been meaning to pull out my alt. and have it tested. I bought a reman from the local toyota dealer less than a year ago. It should still be under warranty but the trick is to get it warrantied and proving that it isn't functioning well.

My batt gauge flucuates when I used my internal switches (windows,locks, etc.). I kinda thought it was my batt, but since everyone is having the same issue, I'm thinking it's my alt.

Are the connectors for the 80 amp and 90 amp the same? Do the plugs fit? If not, I might as well take this to an alt. shop and have them mod this thing up to a 90 amp+ alt.
 
Joined
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I also have these weird electrical quirks as well. I've been meaning to pull out my alt. and have it tested. I bought a reman from the local toyota dealer less than a year ago. It should still be under warranty but the trick is to get it warrantied and proving that it isn't functioning well.

My batt gauge flucuates when I used my internal switches (windows,locks, etc.). I kinda thought it was my batt, but since everyone is having the same issue, I'm thinking it's my alt.

Are the connectors for the 80 amp and 90 amp the same? Do the plugs fit? If not, I might as well take this to an alt. shop and have them mod this thing up to a 90 amp+ alt.
you can pull your alternator and take it to pretty much any auto parts store and they will test it for free. I wouldn't have an alternator shop work on it, asking for trouble imo. I checked at lunch and with the 90 amp I don't see any change at the voltmeter turning the headlights or heater on or off, but it does move very slightly with the blinkers, I didn't think to check the window switches. I would guess that nearly 20 year old wiring and connectors probably aren't helping.
 
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you can pull your alternator and take it to pretty much any auto parts store and they will test it for free. I wouldn't have an alternator shop work on it, asking for trouble imo. I checked at lunch and with the 90 amp I don't see any change at the voltmeter turning the headlights or heater on or off, but it does move very slightly with the blinkers, I didn't think to check the window switches. I would guess that nearly 20 year old wiring and connectors probably aren't helping.
That's what I would end up doing. Pull it out and get it tested. I'm thinking that a reman alt from the dealer would do this kind of things. It should be as good as new.
 
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NE Ia.
 
 
Marco7.. Moby (you have a golden?, if recall) And ALL !!

Hey ALL, nice to see someone else in SAME boat. (or should I
say, sorry I brought up). As for having it bench tested, last 3
mo. I pulled it TWICE this winter and took back to test, and both
passed. Yet after talking to someone other than a bench tech.,
I guess Alt.'s came with a graph (like a dyno output) that showed that Reman. units output through the ranges. Not any more.

My problem this winter, freek'n stranded me 3 times w/ a new Diehard Gold. A full elect. syst. check in Fall showed my Old Alt.'s Diodes going, so I got a couple more months on it till past DEC. and hence replaced. I couldn't even run around town or
hit stop/go traffic at 0°F or below. 2-3 days of that, and would need a jump and have to recharg the NEW bat. with this new Alt.
Recharged this new bat. 4 times, and just parked in Jan.
So, on trips, it's doing it's job. All is fat and happy, as they say.

In my case, w/ the prev. DENSO that was in, I NEVER had this problem. It showed up AFTER I replaced with this O'Reily Reman.
So, it's somewhat comforting I can join the rank's w/ ya all.
I too, have ALL the issues listed in replies...
Intial high idle it's reading like it should.... then....as ya all know.
And maybe just an issue with low output on idle, and also first
thought about the wheel/pully size. So even matched the prev. DENSO with this unit when I purch., & SAME as was prev.

My other White 92's Alt. failed when I was selling, so put one in from "Parts America". That rig, before and after, never showed these drain issues. Yet did get a call 1 year later from buyer
that alt. failed. Thankfully, was in W. Virginia to avoid.

As of last Thurs. Eve. I pitched a &*#! and O'Reily was to get the 90 amp., OF COURSE, the 80 was ordered. So on second for now. So after running around Thurs. night & all day Friday (wife used), I see NO change. Same issues you all report, as did I.
with this second reman.

I'd buy the 18 year old wiring idea, yet why has this showed up now, and wasn't an issue with the prev. alt. ?? ( guess my ????
as I stare into the gray rig, or is it a gray fog -- starting to look
same.

In a tech. bul. I came across, it sayed to KEEP the Condensor off your old alt., and put on the new. Of course, I read the Bul. 3 days after I installed, and the Core was already shipped.

Well, I'm def. going to have to just work on this.
I appreciate ALL the idea's and options for going with other.

MOBY..... mind if I ask what $$$ you have in the 175 / 80 case ??
I like the idea, since I'd like to get lights and a second bat. down road. Also recall, you had the head w/ a crack in port.
I've just logged about 3K on the top-end rebuild, and going so/so if I could just keep the elect. reliable.

Back to some hose repl. work I skipped during the top end rebuild.
Later All....

Geoff T.
 
Joined
Oct 20, 2005
Messages
308
Location
TX
Marco7.. Moby (you have a golden?, if recall) And ALL !!

Hey ALL, nice to see someone else in SAME boat. (or should I
say, sorry I brought up). As for having it bench tested, last 3
mo. I pulled it TWICE this winter and took back to test, and both
passed. Yet after talking to someone other than a bench tech.,
I guess Alt.'s came with a graph (like a dyno output) that showed that Reman. units output through the ranges. Not any more.

My problem this winter, freek'n stranded me 3 times w/ a new Diehard Gold. A full elect. syst. check in Fall showed my Old Alt.'s Diodes going, so I got a couple more months on it till past DEC. and hence replaced. I couldn't even run around town or
hit stop/go traffic at 0°F or below. 2-3 days of that, and would need a jump and have to recharg the NEW bat. with this new Alt.
Recharged this new bat. 4 times, and just parked in Jan.
So, on trips, it's doing it's job. All is fat and happy, as they say.

Geoff T.

Hey Geoff,

I wonder if you have the "Cold Climate Spec" cables going to the batt?
While checking out my LC collision parts list the other night, I noticed that there were 2 types of cabling for all LCs at the batt, with and w/o the CCS for both neg & pos cables.
They're 3 different part numbers by years: 91-92/93-96/97.

Thought I'd mention it since you've had more dire siituations in cold temp conditions.

I'll post part numbers later if you'd like.

When I replaced the single ring connector terminal at the altthe last time, I found that one of the wires had corrosion(green) in the strands for about 10" of the lead. I cut it down to the point where there was no longer any corrosion and then splice in a new wire to the old ring/eyelet connector.
The guage of the new spliced wire looks to be just a hair narrower than the old one, so this may be the cause of the problem. It was all i had at the time and I needed it to be running the next day.
I think the new wire is 8 guage. If I had a souce for new ring terminals, I'd change it out to a 6 guage wire to see if that makes a difference.
 

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