im on my 3rd alternator in my 88 iroc, and i am at an end, i have no idea what to do next, the battery is brand new, the alternator is brand new, its not slipping or anything, i took my first alt to autozone to get it tested and it failed, i bought a new one still wouldnt charge, took it back thinking i bought a bad alternator, got a new one had them test it before i bought it and it passed all tests, but its not charging either, its like its not even on, because i tested the battery after jumping it off and im only getting 12.5v steadily dropping down to 8.4 volts and shortly after the engine dies, i tested the volts coming from the alt and i was getting the same as the battery, so basically i read the voltage from the battery meaning im not getting any current from the alt to the battery, and there is no way my first, second, and third alternator were all bad

anyone have any clue?

oh btw, someone rigged the wire from the voltage regulator coming out of the back of the alt, so im guessing that might be one thing, but where does that wire go? it looks like it runs into the wiring harness and down to the starter but im not sure

thanks

-steve

 

Your CS alternator needs a connection from the ALT idiot light and a sense line to work. Google for "CS alternator help" or try this page: http://www.chevelles.com/techref/tecref14.html

 

The brown wire in the alternator connector needs to have 12V on it. Normally, that brown wire is fed from the FAN fuse (yeah, don't ask why GM chose that fuse specifically). If the fuse is blown/missing, your alternator won't be charging.
If the fuse is good, check the voltage on the brown wire at the alternator connector, you might have a wiring problem then.

Hope this helps.
Lou

 

I had the same problem with my car but I only went through two alternators. I had an electrician look at it and some of the wiring was all fubar. Be sure to check all the fuseable links going to the posts.

 

alright thanks a lot guys, ill check all this out and get back to ya, where would the fan fuse be, all the letters on my fuse box are worn off, i can hardly read what fuses are which

thanks again

-steve

 

on mine its the second column from the left, top fuse.

 

yeah that was it, i could sorta read where it said fan, and its not the fuse, but its too late to go out and check wiring and voltage, ill get to that tomorrow afternoon and hopefully figure something out

again i really apreeciate all the help

-steve

 

ive been having a similar problem but i think it has to do with a cable that's not connected to anything i charge the battery and itll keep its charge for a couple of hours depending on what i have on at the moment the alternator is set up like this at the moment this i got this car from some one for $300 who knows if he played with the cables to im trying to bring it back to life but i need to get past this little roadbump first

 

Dude, the open white wire in your drawing is the brown wire BigBabyLou was referring to. It needs to go to an ignition source, maybe via a resistor or a charging lamp, depending on what car you got.

 

i have a 1982 firebird with a 6 cylinder 2.8L
i dont mean to be so nooobish but i honestly know absolutly nothing about cars so ignition source means? like i said im sorry i do wish i did know more but truth is i dont

 

Spitdude, you will need to find the "left lower" brown wire on the Choke Heater relay in the engine compartment and connec the white wire there.
http://www.austinthirdgen.org/mkport...ine_wiring.gif

That's the best I can do without actually standing over the engine compartment myself.

Hope this helps.
Lou

 

ok i checked the voltage coming from the brown wire while the ignition was on and got 7 volts, which is whats coming from the battery as well, its drained that low, but at least i know that there is not a break in the wire from the alt to the battery

does anyone know if the circuit runs through the headlight switch?

 

According to the diagram, the wire should not be going through the headlight switch at all.

Lou

 

well im stumped on this one.. thanks again for all the help

-steve

 

Oh, I see why you're stumped. Cheby also used the brown wire color for the park lamps!
That would be the wrong wire.

You need to find your choke heater relay and find the brown wire on that connector and trace it to your alternator.

Lou

 

well someone rewired the alternator regulator wire, so its brown coming out of the alternator but is spliced with a red wire, and i dont have access to a car lift or an engine lift, and i cant get a good look at the wiring harness to follow the wire with the engine in, and i cant get under the car to try to get a decent look at it

does anyone have a wiring diagram for the charging system for this car? by any chance?



i think something is blowing out my alternators, just a feeling, i took off the alternator i just bought and im going to get it tested today sometime to see, because i know it was working before i installed it

also i tested the battery just out of curiosity to see how much the voltage had dropped, 8.15v im getting from the battery and from the L wire on the alt, but when i take the L wire off of the alt(this is using the one wire setup) i get 9.18v from the battery and 9.18v from the L wire(the wire in the pic)

anyone got anymore ideas?
i really hate going outside and seeing my car just sitting there rotting

thanks again
-steve

 

I am having almost the same problem on a 88 'bird 305 TBI.

 

well i took the alt to autozone and it failed, so something is blowing out my alternators, i went ahead and got another new one, so this makes it the 4th one, but im hoping i can find the problem before i install this one

 

have you checked all the fuseable links by the battery ?

 

where would the links be, i cant find them, i found one and its fine, i tested it with a voltmeter to be sure

this wiring is all rigged, splices everywhere, ive been trying to get ahold of the guy who owned it before i did, so i might be able to get him to help me out a little, since he was the one who rigged it.. i assume anyways.. thats also why im asking if anyone has a wiring diagram for the wiring harness in an 88 iroc, or at least a wiring diagram for the charging system

 

can you get me a larger picture (show from the alternator and plug to the point you have here, I may be able to figure it out, I see a possable problem, but want to make sure,

PS my Vert is an 88 as well so if worse comes to worse we can conect via phone and talk you through this. and did your car come with a carb? I thought all 88's were EFI?

 

Is there voltage on the wire splice even with the key off? That would be wrong and the possible cause for blown alternators.
The brown wire needs 12V from a switched source (ignition) and it gets it usually from the FAN fuse (in case the vehicle has electric fans).

Diagrams here:
for VIN T: http://www.austinthirdgen.org/mkport...T_charging.jpg
for VIN E: http://www.austinthirdgen.org/mkport...E_charging.jpg
for VIN F and 8: http://www.austinthirdgen.org/mkport...8_charging.jpg

Hope this helps.
Lou

 

awesome, thanks for the diagrams

yes there is voltage when the key is off, im getting the same amount of voltage from the spliced wire as im getting from the battery directly, and you say it goes through the fan fuse, well my fans are rigged too, theyre run directly from the battery, theres a switch that someone rigged to turn them on from the inside, i checked the fan fuse and its not blown i even replaced it with a new one just to be sure, but i guess thats a pretty big clue there

macertheracer, i got some more pictures, but theyre not the best, my cameras lens wont come out so i had to use my phone, and if youre thinking about that wire that is cut off at the end of the harness that could be something, but the alt was working fine before without it, but anyways its a white wire, the alt may have had 2 wires running to it once before, but the plug that was in the alt only had one

oh and no it wasnt originally carbed, someone converted it, i found parts of the injection system and other electrical parts in the back after i bought it, id like to convert it back

but anyways the plug is ripped off in the picture, i ripped it off because it had glue **** all in it, so i ripped off the plastic and tried to hook the clip from the wire directly to the alt, didnt work, ill get a new plug when i get all this figured out





thanks again for the help

-steve

 

ok how about this, I have a TPI wiring harness and ECM out of a 1986 bird (should be real close to the camaro harness, like identical) , and a 1986 Z28 we could strip the under hood body harness out of, so you could start over.... for a price may be your best option, Or we could keep going like this, its your choice. and I am ok with helping but if you want to go TPI anyway, think about it? and looks like a real butchered up mess. the tan or brown wire that is cut off at the tape in the top picture I believe is your Brown wire for the alt "that is what I was looking for", check it for voltage, with key off and then key on, if there is no voltage present with key off and voltage with key on you got it. then the red that is cut off goes to the alt plug as well

 

well kinda short on cash right now, but id take you up on it if i had the cash, lol, and the tools to do it with, i want to restore the car, but im gonna have to get some more money coming in first, so im going to try to make do with what i have until then

but yeah i tested all the voltage and everything already and im getting the same amount of voltage with the key off as i am with the key on, about 9.15 volts, well less voltage with the key on, so theres a problem in the switch somewhere or something, im guessing

 

ok I'll get pictures tomorom for you of my wiring to compair notes, cool?

 

yeah thatd be kool, then i could get an idea of what things should look like under there

i just figured something out though, i took the voltmeter out there again to check voltage from the fan fuse, and i am getting power from the fan fuse when i switch the key on, but im getting nothing with the key off, so thats working right, i found 2 wires that were spliced off inside the wiring harness, i tested the voltage from them i got 9.18v(thats whats left in the battery) from one and nothing from the other, the wire i got voltage from is brown with a white line, the other was just plain brown, anyways, i pulled the fan fuse while the key was still on and i lost voltage from the brown and white wire, so would this brown and white wire be the wire that the alternator is supposed to be hooked too? whats the purpose of the red wire that is spliced that was originally hooked to the alternator? and whats this other brown wire?

i got a couple pics to show what im talking about

 

Bingo!!! that is them, good job of investigating, I have the pictures at home, (I'm at work now) but those are the wires that are connected to my alternator, red is hot at all times, brown wire goes to the guage the other excitates the alternator, (makes it generate electricity) I did check the voltages with key on , and key off, had the same exact results as your latest find. if you go purchase a new plug you will find the same three colors of wires comming out of it. if you have problems let me know.....................The Racer ................. and I will post the pictures later tonight, for you. PS I was thinking about you and this problem today and had a plan: I was going to have you start at the firewall connector and look for these wires, but you beat me to it I am impressed with your tenasity, stay with it, as long as it aint wrecked, there is hope!

 

awesome, looks like im making some progress, lol, thanks a lot for the help.

there is one thing i dont understand though, the alternator worked before, with just that red wire attached, i wonder why it all of a sudden doesnt work right anymore... well im gonna give this a shot, going to go pick up a new plug right now, see if it works

 

Exactly! That's what makes the alternator charge.

Red wires usually have constant power, with key on or off. That was the wrong wire for the alternator charging in the first place.

Lou

 

ok i bought the plug, but its wires are different, it has the big red wire, but the other 2 are solid brown and solid black, so that white and brown wire that goes to the fan fuse.. which wire does that connect to on the regulator plug? and which wire does the solid brown wire connect to? im guessing it hooks to the brown wire, lol, but just makin sure, id hate to blow out ANOTHER alternator because of some stupid mistake

 

the middle wire on the plug is the same as YOUR brown or tan w/white stripe the red is self explanitory and the last is YOUR solid and you should have it fixed. I remembered because I was looking at it today.

now what is next on the agenda?

 

kool, thanks

well next, i guess im going to hook it all up tomorrow and then jump it off and see if it charges, i really hope so

 

here is the picture I tried last night but the ISP was down

http://www.flickr.com/photos/tinbender59/3465980444/

 

so for mine, it would be solid brown to solid brown, red to red, and black to brown/white.. i got it hooked up that way, i havent connected the battery yet

again, just making sure, ive made too many mistakes already lol, one of them being today, trying to put the belt back on, make a long story short, i punched myself in the face with a wrench, hurt, lotta blood, but i got it on there, lol

 

That sounds about right.

However, if you feel like swapping the black and brown wires (to conform to the color code), it's not hard to pull them out of the connector and resolder. The brown wire is usually in the middle and your current configuration will be a little confusing. But I'm not forcing you to do the color swap, only suggesting to avoid future confusion.

Lou

 

haha! wooo! it works! checked the voltage after jumping it, got 14.92v from the battery, i am mobile again, yes!

thanks a lot guys, im forever in your debt

now my next feat is to rewire the fans correctly so theyre not rigged

again thanks a lot, man this is a relief

-steve

 

gud job....nothing like fixin it urself and gettin over that hump

 

Congratulations on job well done.
Glad you got it finally working. Enjoy the great feeling of accomplishment!

Lou

 

hey Wizard check out my project here http://www.flickr.com/photos/tinbender59/sets/

I picked it up for $1000 and have been driving it everyday for the last 3 months, getting over 20mpg I plan a rotissery and stripping her down to bare metal, fix the problems and improving some enginering short falls then repaint metal flake dark blue.

 

you have 2 projects there that look nice, i would love to have a 3rd gen convertible, i didnt even know they existed until i got this iroc, real nice, all different colors, but hey its a project, looks straight, itl look great, i like the idea of the metal speck blue, im planning on painting mine a dark red with metal specks, or green metal specks, not sure yet, call it the hulk, lol

i also like that green car, the 51 keiser dragon, ive never seen one before, but looks like a real fun project, youd look real slick cruising in one of those restored

by the way.. i never really properly introduced myself, i just came here hoping for help, lol, sort of long introduction, im bored, i dont work tomorrow, and its almost 1 in the morning

im 20 years old, names steve, this is my 5th car after 3 real pieces of crap embarassing fords(87tbird, escortlx, 85mustang lx), and a toyota pickup, i like my pickup just because of the gas mileage and the fact that its a truck, but my moms now driving it around so i dont really have it anymore, plus ive always kinda been a chevy guy, was raised that way, anyways, when i was 13 my friend in the army had an 86 camaro with t tops, ever since he got that car i had been jealous of it, ive always loved the 3rd gen body style, then i got this one, and believe it or not i spotted it in a field in deberry tx while i was going to pick up a friend in my little 86 toyota pickup, lol, well i passed it up and on the way back i stopped by a house next to this field and asked this guy about it, he said it was his ex wifes and it had been sitting there since 2003 and it probably didnt run anymore, and he actually asked me if i wanted it, lol, i said itd be nice, i asked him how much and he sold it to me for 200 bucks with the title! i had it towed here, and all i had to do was drop and clean the gas tank, change the oil, put new hoses on it, coolant, a battery, and some gas and it blew my mind when it started up, i could not believe it, and it sounded great.. i actually took the chance to drive it to the dmv to get the title taken care of and registered.. shouldnt have.. it over heated and spewed coolant everywhere, anyways i made it there and got it registered and a friend of mine came and picked me up, and a few hours later i went and started it and drove it back home, and it spewed fluid as soon as i got it home, then i found out the fans werent coming on, i eventually found the switch that someone rigged to turn them on, and that stopped the overheating, so that was a relief i was afraid of a blown gasket or something, so i drove it around like that for a while, it still had some kinks i was hoping to work out by driving it around for a while, thats when i ran into this alternator problem, and of all places it died on la-7172/i-220, and i was stranded, at 1 in the morning, with no phone, i actually ended up walking in pitch black, i found a gas station and asked to use the phone, about 3 hours later someone finally picked me up, and we towed the car home, 4 in the morning, didnt get back til 5, and i started this thread after buying my 3rd alt and it not working, so i started to search the web in hopes to find a clue

anyways, thanks for everything, and i look forward to becoming a part of this message board, learn some stuff i dont know already

 

Congratulations on your new toy!
I see that you're looking for the spacer rod for the top. Is yours broken or plain missing? If broken, it can be welded. If missing, you can make one out of 5/16" round stock, with the help of a torch. Then just thead the ends, put nuts on them and you're done.

Lou

 

thanks Lou both are missing on my carI am thinking of reengenering a set that wont "invert" I think I have it figgured out, I'll keep you posted, although it would be nice to have at least one to compair to.


thanks wizzard I will post a "history " on the Dragon, it is rather lengthy and I gotta go meet a fellow to pick up a bail of hay for the "girls"

 

So his cure for the problem was that the Solid Brown and the Brown and White wires were not connected to his alternator right?

Reason I ask is...
I'm having the same problem as he did on my 91, 305 TBI.

Everything was working fine. My old alternator would still charge, but the bearings were going out on it.
I installed a new one and everythign was fine for about 30 miles after the install when I noticed my volts had dropped in the car.
So I put my old one with the bad bearings back in the car and once again got normal readings on the gauge.

Had the new alternator tested and it failed.
They gave me a replacement which I did not have time to install during lunch.

Since my old one was still charging... I figured... I'll install the replacement I got today while at lunch tomorrow.

So I go driving home with my old alternator in the car and all of a sudden it drops voltage too!

What could be killing the alternator?
All my wires are properly hooked up.

I don't wanna keep buying new alternators like he did.

There is a good chance I got a dud alternator out of the box and that my old one was on it's final leg. But after I install this replacement they gave me, and it blows... then I'm stuck having to buy another alternator until I get the problem diagnosed.

Could a old belt possibly be the culprit as well and blow out a new alternator in only 30 miles of driving?
It has been a few years since I've replaced the belt.
I'm going to buy one before I install the new alternator.

Side note... When I say new.. I'm meaning rebuilt new.

Thanks for any info.

 

well let's qualify rebuilt, if you are getting your's from the three guys on the corner, or the Irishman, or any one in the Zone, you will more than likely have another failure. This is one of those things that I learned a long time ago, I am now 50, GO TO AN AUTHORIZED "AC" OR "GM" rebuilt parts center for the big ticket items. when I work on someone elses car I will not do it if they want to go on the cheap with belts, hoses, accessories, or starters. simply to da^^ much work and I don't need the agravation. buy quality and you are garanteed at least a year, with no trouble out of the item. plus I spent to much money on my auto's to chance blowing a hose or belt in the summer, and loosing a motor because I saved $12.00 on a hose. just my "inflation you know" as for your question: no; he was blowing alternators because they were not hooked up properly, if your plug is still in tact that should not be your problem, you just need to poney up and purchase a quality unit

 

Any chance you are putting the plug in backwards? If the rectifier is hooked directly to battery power it will fry in short order.

 

i have an 89 iroc 5.7, 700r4 trans, and my car is not charging. i noticed my connector on the alternator has a red and brown wire, but no black and it is not cut out of the conector. do i need that black wire, is it a gnd wire.

 

on mine the wire inside the harness wasnt black, just the wire on the plug was black, the wire that the black wire on the plug connected to was tan colored with a white line on it, see if you can find that wire inside the harness, if you do find it, you should be getting about 12v or the same voltage the battery has, from it with the key on, and nothing from it with the key off, the red wire should always be getting about 12v, again the same as the battery directly, no matter if the key is on or off, and the brown wire im not too sure what it does exactly, but i didnt get any voltage from it at all when i tested it, if you get it connected and all the voltages are as they should be, and it still doesnt work right, then it may be the alt itself...

but hey, i just figured all this **** out myself, ive only had my iroc for a couple months now, im just learning off these guys, i think ive got it covered, but you may want to wait until someone confirms it, lol

 

thr plugs are keyed or molded to go only one way so reversal is not likely

 

if the cars factory wiring did not have it you do not need it the "corect" alternator will work fine, it is designed to work with out the black