How.to Read a Witring Diagram on a 1979 Toyota Truck

Topic: 1979 Toyota 4WD Pickup alternator/regulator/wiring issues  (Read 32925 times)

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A mechanic replaced the alternator and regulator in my truck, and within a few weeks I was having issues. The voltage is fashion too loftier (about 16.5 volts) which makes the battery overcharge/bubble/leak. If I disconnect the regulator, the engine'southward idle speed increases and the voltage drops to a picayune over 12 volts.

I was told by the mechanic that the alternator'due south 3-pronged plug is LEF rather than the more common FEN. The regulator he used was an Autozone VR756, which corresponds to the Toyota office numbers 27700-38110 and 27700-38113. This is for the 55 amp alternator (I don't know if my alternator is 55 amp or non, but apparently the mechanic thought so) and has a 5-blade connector. I accept ordered a new Nippondenso regulator which corresponds to the same Toyota office numbers that the VR756 does; but I'm concerned virtually the wiring; and I am besides concerned about not knowing for certain exactly which alternator I accept, and exactly which regulator I need.

Here are some pictures showing the questionable wiring and other things:

Can anyone offer some advice and/or pictures of a correct setup? All of the variables here make this a very frustrating problem; i.e., there are regulators with v-blade or 6-blade connectors (and they will both physically plug into the same mating connector); there are regulators intended for 40-amp and 55-amp alternators; so there are of course 40-amp and 55-amp alternators; and there are LEF and FEN plug configurations. On top of that; I don't even know if it is all wired correctly (see higher up pictures).

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thats the biggest butcher job i accept ever seen.

you lot need to get by the BBB in your area and plough his ass in

79 trucks had a 40 amp alternator and the regulator had a light-green plug

cant recollect if it was 5 or vi wires but DAMN

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PLEASE post the proper noun /business concern of this self proclaimed mechanic and so no one else always goes to him for anything

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AR-TTORA founder 22R bored.060,LCE stage 2 race cam http://pure-gas.org/    32/36weber, Marlin 1200 Not ceramic clutch, L52SHD+dualcase #2919, cable-locker, Yukon 5.29 gears, 35'due south, Allpro ebrake, front springs, and high steer, F150rears    RIP Nitro ix-29-07   I sure miss him MarlinCrawlerInc IS Non affiliated with TrailGear in any mode

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    even drunkard i would not do that to some one I do non similar

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thats the biggest butcher job i take ever seen.

you need to go by the BBB in your area and turn his ass in

79 trucks had a 40 amp alternator and the regulator had a greenish plug

deceit remember if it was 5 or 6 wires but DAMN

On every autoparts place and site, and even at two Toyota dealerships, when I've checked for a regulator, in that location is the option for a regulator that goes with a xl amp alternator and a regulator that goes with a 55 amp alternator; for 1979. In that location is also the 5 and half-dozen blade choice for 1979, simply I'chiliad not certain if that is two extra options or non. I'thou thinking that mayhap the 55-amp version has 5 blades and the forty-amp version has 6 blades on the plug.

Please post the name /business organization of this cocky proclaimed mechanic so no 1 else always goes to him for anything

I think he was trying to make exercise with the previous possessor's hack job. I'd just bought the truck knowing that the alternator needed replacing, which he did, and replaced the regulator too. It was a few weeks before the voltage started getting too loftier.

I'd actually like to know how to make this correct. Does anyone know what specifically is wrong (if anything) with the wiring between the regulator and alternator (besides it being an ugly hack chore)?

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"a few weeks till information technology went bad"

i would say the autozone regulator  died, they can and do go bad

ive had ane go bad in 2 months and current one for 3 years

you can perhaps notice a un-chopped harness somewhere and replace the mess with it

fwiw  my 79 has the 40 amp, green plug on alt and reg

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AR-TTORA founder 22R bored.060,LCE stage 2 race cam http://pure-gas.org/    32/36weber, Marlin 1200 Non ceramic clutch, L52SHD+dualcase #2919, cable-locker, Yukon v.29 gears, 35's, Allpro ebrake, front springs, and loftier steer, F150rears    RIP Nitro 9-29-07   I sure miss him MarlinCrawlerInc IS Not affiliated with TrailGear in any way

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"a few weeks till it went bad"

i would say the autozone regulator  died, they can and do get bad

I'm hoping that that's all that's wrong. Like I said, I have a new Nippondenso regulator which corresponds with the aforementioned Toyota part number that the Autozone regulator did, coming in the mail.

fwiw  my 79 has the 40 amp, dark-green plug on alt and reg

That's what I'd like to practice, but it seems that this alternator is uncommon (information technology took the mechanic a couple of days to go ane, considering all the parts stores had the "FEN" alternator in stock, but the "LEF" alternator, which he said I needed, was special order); and I don't know how to place the correct alternator and harness like say, in a junkyard; and I peculiarly don't know what to enquire for on the phone when calling a junkyard.

« Last Edit: April nineteen, 2009, 06:13:01 PM by MaximRecoil »

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Okay, the new regulator has fixed the high-voltage problem, at to the lowest degree for now (13.half-dozen volts at the battery, which is excellent), only there is another trouble. The truck won't close off with the key when the regulator is hooked up (it doesn't "diesel"; it just continues to run normally as though you hadn't touched the cardinal at all). The onetime regulator that was over-volting did the same thing. If I disconnect the regulator, the engine turns off with the central every time.

The engine is very stripped down (all of the original emissions equipment is gone, and a Weber 32/36 carburetor is in place of the stock Aisin carburetor). This was done long earlier I got the truck. I've heard there was something unique about how these trucks turn off; something like a fuel-shutoff solenoid or something? If that'southward the case, I'm certain mine doesn't have that. Notwithstanding, if that is the case/problem, I'grand not sure how that relates to the key working to turn off the truck with no regulator fastened, but not working to turn off the truck when at that place is a regulator attached.

Edit: Scratch that. When I started information technology this morning the voltage was back up to 17 volts. I suppose the wiring is probably wrong; or something is incorrect somewhere, and it is ruining regulators. I don't know what to do virtually it. I doubtfulness that even the Toyota dealership would exist able to fix it (I don't retrieve those wiring harnesses are available new).

« Last Edit: Apr 21, 2009, 09:13:14 AM by MaximRecoil »

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Information technology sound like the regulator is messed up. If i were y'all id get an united nations rigged harness and start over.  BTW my 80 pickup has a six prong connector and a forty amp alternator. I know the 55 amps were avabile but ive never personally seen one. Ive got a 80 FSM then if you need whatsoever more than info on wiring or whatsoever diagrams permit me know.

To aid reply the problem near the regulator hooked upward or not and the truck keeps running has nothing to practise with the fuel shutoff solenoid. Its for california models when you let off the gas when at speeds information technology prevents more fuel from inbound the carb and stops overheating and afterburing in the exhaust.

The reg hooked up or not when you endeavor to shut information technology down is creating a curt to power and dorsum feeding the system with power keeping it running.

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It sound similar the regulator is messed up. If i were y'all id get an united nations rigged harness and start over.  BTW my 80 pickup has a six prong connector and a 40 amp alternator. I know the 55 amps were avabile but ive never personally seen one. Ive got a 80 FSM then if you lot demand whatsoever more info on wiring or any diagrams let me know.

A scan of the wiring diagram for both the 55 amp and the 40 amp alternator would be cracking, if it is non too much trouble. Exercise you call back it is the same wiring for the 1980 as for the 1979?

To assist answer the problem well-nigh the regulator hooked upwards or non and the truck keeps running has nothing to exercise with the fuel shutoff solenoid. Its for california models when you let off the gas when at speeds it prevents more fuel from inbound the carb and stops overheating and afterburing in the exhaust.

Ah, okay. Cheers for the information.

The reg hooked up or non when yous effort to shut information technology down is creating a brusk to ability and back feeding the organisation with ability keeping it running.

Interesting. Where do you suppose the short is located? When I first got the truck dorsum from the mechanic with the Autozone VR756 regulator, the truck close off with the key most of the fourth dimension, simply occasionally it would non. The problem got progressively worse as the voltage was getting higher and college, to the signal that it would never shut off with the key with the regulator hooked up. And so maybe it was an intermittent short at first which somehow became permanent?

The problem followed to the Nippondenso regulator that I installed recently. Even for the mean solar day it was doing the correct 13.6 volts, the truck would not shut off with the key; so that seems to indicate that the brusk is somewhere in the wiring, rather than in the regulator? If that'south the instance; I don't see how the short is only present when the regulator is hooked up though. I suppose the brusque could be in the regulator, and it was created instantly (or within a minute or ii) in the Nippondenso regulator; just took longer to create in the Autozone regulator.

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i have an 82 pickup, the alternator worked fine for about two and a half years afterwards i had bought the truck. eventually something short circuited because of shitty one-time wiring. i tried for over a calendar month to find out what the problem was, and after i had tested every part of the stupid charging system, i was so tired of information technology that i scrapped ALL of it and converted over to a ford alternator.

if your motor is already stripped downwards, this is a not bad conversion. the alternator i got is a Ford 3G 130 amp from a lincoln continental. twenty$ at the junk k, and it fifty-fifty had a new regulator on information technology.  it has one wire that goes to the positive battery concluding, a footing wire, and two other wires that just loop off the alternator to a different spot on it. so yous just have to hook upwardly 2 wires, and make a bracket.
i highly reccomend doing this if you lot are tired of fighting the shitty sometime toyota charging applied science. external regulators are gay

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82 hilux, bobbed, really fast 22r, two transfer cases, ARB'south, five.29'due south, 37" MTR's. Custom everything.

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Ill endeavor to become scans of those wiring diagrams up shortly. Im remodeling the firm then stuff got moved around but im certain i know were the scaner at.

I call up that the brusque is in the wiring mess that goes betwixt the regulator and the harness. endeavor to fix that up then come across what happens.

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That's a great mod at that place, 82 hilux ... I was going to suggest raping a junk yard truck and splicing in what has been hacked, wiring takes patience and shrink tubing  . My girl has a 79, I'll try to get some pics of the regulator set-up; I replaced information technology/alternator a while back. Information technology was ten tons of fun driving it dorsum home (about 30 miles) with a dead alternator... on a snowy dark . Luckily her dad permit u.s. use his F250 as a 'chase vehicle'; when the lights went out I'd pull over and jumper cable-charge the battery for a few minutes, then bulldoze on. Repeat as needed.

Fun times... proficient luck!!!
Dan

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IronClad: If I wanted to concur hands and be nice I'd become a hippie.

85 4Runner, duals, 38s, 5.29s, locked, 3.four swapped, GranVille Edition

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thank you. you lot only go to the junk chiliad and find the biggest lincoln automobile you can, or ford thunderbird. every bit long as its a ninety something and has lots of fancy features in the car (electric windows and locks, digital dash, A/C) it will take the 3G alternator. 130 amps. $21.  2 fawkin wires to hook upward!

i cant run into why anybody would rather take a toyota alternator when the conversion is And then Simple, but thats just my opinion.  ive had really bad luck with my truck and shitty toyota alternators. i fifty-fifty broke i in half from wheeling too hard. i absolutely H A T E the first gen external regulator charging organisation.

its very rewarding to rip all that external regular B S out. i highly reccomend it!!

« Last Edit: Apr 27, 2009, 10:42:34 AM by 82 HiLux »

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82 hilux, bobbed, really fast 22r, 2 transfer cases, ARB's, five.29's, 37" MTR'southward. Custom everything.

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if it helps, i have a printout from World wide web.ALLDATA.COM of the whole first gen toyota wiring harness. i can scan it onto the computer and post it upwardly. its pretty dang helpful

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82 hilux, bobbed, really fast 22r, 2 transfer cases, ARB'south, v.29's, 37" MTR'southward. Custom everything.

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cheers. yous only go to the junk m and detect the biggest lincoln car y'all tin, or ford thunderbird. as long every bit its a 90 something and has lots of fancy features in the car (electrical windows and locks, digital dash, A/C) it will have the 3G alternator. 130 amps. $21.  two flopin wires to claw up!

i deceit see why everyone would rather have a toyota alternator when the conversion is SO SIMPLE, just thats just my opinion.  ive had really bad luck with my truck and :pokinit:ty toyota alternators. i even bankrupt one in one-half from wheeling too hard. i admittedly H A T E the kickoff gen external regulator charging organization.

its very rewarding to rip all that external regular B South out. i highly reccomend it!!

It sounds like a great idea, except fabricating a bracket is beyond me, and also, with a 20R, I'g already light on horsepower, and I'd be worried virtually the extra burden of a 130 amp alternator on the engine, every bit opposed to a twoscore or 55 amp alternator. Too, some of the wiring in the harness that runs betwixt the alternator and the external regulator heads off into the rest of the wiring harness. How would you bargain with that?

if information technology helps, i have a printout from WWW.ALLDATA.COM of the whole beginning gen toyota wiring harness. i can browse it onto the computer and post it upward. its pretty dang helpful

That would be bully, thanks.

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ok I am gona try to throw something in here  I had this very same problem  and it kept me running in circles then finaly MARLIN and I spoke on the telephone over this.

1st what type of plug exercise you lot take on the back of the alti. ?

2nd what type of regulator plug do you have ON THE TRUCK HARNESS SIDE ?

I have gone into not bad depth on a thred on this site  ALL 4WD alti. that were produced from 1979-1983

what nosotros have learned so far has now been able to come into calorie-free as we volition all encounter in this msg.

I recently spoke with Marlin and Jon82toy on the telephone about my 1st gen truck non charging well I constitute out that I accept the wrong alti. on at that place I had the GREEN ALTERNATOR that you lot will see in this film here.

this is the plug style for the Light-green ALTERNATOR

These alternators are used on trucks with the years of 1979-to 1983 4x2'due south these alternators only put out 40 amps

Yet the other alternator that Toyota used in the 1st. Gen trucks had a BLACK ALTERNATOR as seen in this picture hither.

This is the plug style for the BLACK ALTERNATOR

These alternators are used on trucks with the years of 1981 to 1983 4x4's these alternators put out 55 amps
BOTH OF THESE ALTERNATORS Use A EXTERNAL REGULATOR THAT GOES WITH THERE Colour CODED PLUG ON THE Dorsum OF THE ALTERNATOR

Yet the both look the same from the front and sides other than the light-green or blackness stripe and the plug they are very diffrent and should non be used in whatsoever other year trucks that they were fabricated for or else they volition not do the job they were intended to do. I accept not installed the relay in the harness that has the "open circut" that is keeping the alternator, charge low-cal, and external voltage regulator from working correctly due to the fact that I had to order this from Toyota and it has not come in at this time I will take a part number on this as soon equally It comes available to me.

if you need more information pllease experience free to read my thred
http://board.marlincrawler.com/index.php?topic=50416.msg638431#msg638431

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IF YOUR LOOKING OUT THE Front OF YOUR 4X4 AND YOU Cant Meet THEN Merely Plow ON YOUR WIPERS. But THEN THINGS Become ALL MESSED UP Similar IN LIFE.

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yep dark-green alts are 4x2 40amp black are 55amp 4x4

I had an electrical trouble this weekend at the hammers, threw money at an alt later an incorrect diagnosis. an easy way to check an if alternator is charging is to contact the back of the alt with a piece of metallic (screwdriver etc) if the alt is charging information technology will create a magnetic field. Mine was not (nor was the new one I replaced it with) and Marlin and I tracked information technology down to a simple blown fusible link. fusible links are very hard to tell if they're blown because they look like a standard insulated wire even when blown. information technology was a existent caput scratcher but THE MAN handled it. Thank you again Marlin

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i retrieve marlin is the god of toyotas

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82 hilux, bobbed, really fast 22r, two transfer cases, ARB's, v.29's, 37" MTR's. Custom everything.

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On my 79 In got fed up with the stock alt. and regulator and swapped to a gm. Super piece of cake and brighter lights

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Here's what I have in the 79; hope it helps you.

Q? well-nigh the 130 amp Ford alternator... how volition the former stock wires hold up; risk of fire/melting wires?

Dan

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ASE certified shadetree mechanic and spoon operator

IronClad: If I wanted to concord hands and be nice I'd get a hippie.

85 4Runner, duals, 38s, 5.29s, locked, 3.4 swapped, GranVille Edition

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IF YOUR LOOKING OUT THE Front OF YOUR 4X4 AND YOU CANT SEE And so Merely TURN ON YOUR WIPERS. BUT THEN THINGS Become ALL MESSED UP LIKE IN LIFE.

WHEN YOU Get TO THE END OF YOUR ROPE JUST Recall THAT Forth TIME Ago  You WERE THE FASTEST LITTLE SWIMMER TO THE EGG

08:55:22 PM BeccaLoo24 � i like to screw things

$99 scratch and dent drill press has drilled more than holes than Ron Jeremy.

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my alternator has a dedicated power wire, that runs straight from the alternator directly to the battery..... it is an viii gauge wire..... wasnt there in 84, but i added information technology because my alternator was a higher amp unit from an 85

information technology is a seperate wire than what is from the harness... came stock on the 2wd 85's

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i was in a mud hole last week and my CHG low-cal came on, turned out my ALT had died
the next day i put in a bran new one all adept,.... then like 3 hours later my CHG lite came back on, WTF i called the auto parts
store and they said, mabe a bad new ALT so i went out side started my truck upwards, voltage was 18.five i went got a new regulator and
then no more problems

1980 22r swap
hope this mabe helps adept luck

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Same thing happened to me, that regulator was OEM and the alternator was a 'new' re-human. Estimate something had to give... I'll exist checking the yards for a Ford alternator this weekend; will post pics/write-up if anyone'due south interested?

79/swapped 85 22R

Dan

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ASE certified shadetree mechanic and spoon operator

IronClad: If I wanted to concur hands and be prissy I'd go a hippie.

85 4Runner, duals, 38s, v.29s, locked, 3.four swapped, GranVille Edition

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most parts houses have marginal alternators for toyota'southward,

why a ford    fwiw  i run my stock 40amp with regulator on the fender and on the pass side of the engine i run a threescore amp celica, its never on till i plough it on

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AR-TTORA founder 22R bored.060,LCE phase II race cam http://pure-gas.org/    32/36weber, Marlin 1200 Not ceramic clutch, L52SHD+dualcase #2919, cablevision-locker, Yukon 5.29 gears, 35's, Allpro ebrake, front springs, and loftier steer, F150rears    RIP Nitro 9-29-07   I sure miss him MarlinCrawlerInc IS Non affiliated with TrailGear in any way

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I believe I take the same setup y'all do, the cold weather/higher output setup.  I besides went through something similar and kept toasting voltage regulators till I fixed the wiring from the alt to regulator.  It should exist easy enough to do yourself, or y'all could proceed an centre out for the sub harness on hither and ebay.  If you lot don't fully prepare the wiring issue you'll continue to become through alts and regs.

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Cheers to everyone for the assist, and thanks to Maxwe001 for the offer to help over the phone. I took it to a 4WD specialist shop in town that has a good reputation. They put in the more mutual FEN 40 amp alternator (light-green band around it; the onetime one had a black band); made a harness, and used an OEM Toyota regulator with a 6 blade connector (one that I'd bought from the Toyota dealership and tried earlier but it didn't practice annihilation with the 55 amp alternator and existing wiring). This seems to accept fixed the problem, at least for now. The voltage is at about xiii.9 VDC at the battery when the truck is running, and the truck turns off with the key every time. They had a 1979 Toyota wiring diagram which they used to achieve this, and they gave me a copy every bit well.

I don't think at that place is a charge light relay in there though, and then I don't know what to think about that. Should I be concerned?

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when you plow your key to the on position the chg light and oil light should come up on ,
if non you will have to prepare this cause if all the sudden your regulator goes out for some reason you will never  know
hits... when my regulator went out my calorie-free wasent working eather and nail my batt was soooooo hot and bubbling were hissing from it

pritty funny now

promise yous fix information technology the right manner

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IF YOUR LOOKING OUT THE FRONT OF YOUR 4X4 AND YOU Deceit SEE THEN JUST Turn ON YOUR WIPERS. Just THEN THINGS GET ALL MESSED Upwards LIKE IN LIFE.

WHEN You lot Go TO THE END OF YOUR ROPE JUST THINK THAT ALONG Time Ago  You WERE THE FASTEST Trivial SWIMMER TO THE EGG

08:55:22 PM BeccaLoo24 � i like to screw things

$99 scratch and dent drill printing has drilled more holes than Ron Jeremy.

http://board.marlincrawler.com/index.php?topic=48342.0

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