kbrown211

well the saga continues, car died yesterday at work. tested 1 altenator it was no good, replaced with a extra alt i had and it bites the the dust to and i tested it checkers before it was put on. then go to checkers to buy a new one tested it before i left the store, put it on the car when i got home and still no charge, so i took it back today and have another new one but i didn't put it on yet from fear of frying this one to, so what do you fellas think the problem is, also remember none of them have a charge soon as i turn the car on.

J-Rat

iTrader: (2)

First thing you need to check is your battery. If you put a new alternator on a dead battery, there is a 70-90% chance it will kill the new alternator.

NEVER put a new alternator on a fried battery.

Jarrett

*edit* If the battery is good, its time to look at the line that runs from your Alt to the battery. You could isolate that line by disconnecting the charge line, and running another one direct to your POS terminal.

kbrown211

so i can go ahead and unhook the terminal that is on the altenator and just run a new wire from pos post to the altenator post, does this need to go thru a fuse.

J-Rat

iTrader: (2)

There isnt a fuse that I am aware of, but I dont have the wiring diagram in front of me. If memory serves, the actual alternator IS the fuse.

There are several people here (Including me) that run an extra length of wire from the alternator to the battery (its the terminal on the top with the small nut, in case you didnt know). It helps bump up the voltage by bypassing an old length of wire. The reason I suggested this to you is that there may be a possibility that your charge line is getting grounded in the harness somewhere. This will zap an alternator quick, fast, and in a hurry.

So, if it were me, I would verify a good charge on the battery, and bypass that line. If you actuall bypass it, you will need some pretty hefty gauge wire (prolly 10 ga or better). And I am suggesting this for testing purposes.

Jarrett

*edit* If you have possesion and knowledge of a multimeter, you could eliminate some of these problems without rigging extra wires everywhere.

J-Rat

iTrader: (2)

Another thing...Did you happen to have Checkers test your the alternator they sold you and your car supposedly killed, after it was taken back out? Did they verify that it was bad?

kbrown211

yeah i had them test it again today when i took it back and it only put out about 8 volts

kbrown211

well another one went down today, i dont know what the **** is happening, i ran a new wire from the altenator straight to the pos post and i still got no charge, my question is what else does the original wire from the altenator go to because when i unhook the wire there was no power to the car. and before you guys ask i unhook the battery for 2 days and it still had a 11.9 volts. also when i turn on the ignition the idiot lights dont come on, well the only one that comes on is because the door is open. so what else could be killing these altenators.

also i did this rewire
Right now, my white
wire with the black stripe (W/B) is CUT next to the CPU plug. I ran the
Alternator plug's W/B wire to the cut end of the white wire with the black
stripe going to the CPU plug, and left the W/B on the original harness side
hanging, just taped off.

The black wire with the yellow stripe (B/Y) at the CPU is just spliced into,
with the other wire from the alternator.

HAILERS

jpg

HAILERS

hjgh

HAILERS

Now you tell me.....is the eight seven schematics superior to the eight eight or not? I have words for the people who make schematics like the eighty eight schematics. This being a familey site.........

HAILERS

So anyway, the 87 shows the feed wire for the battery splices off and goes to the 80 amp fuse and to the ignition switch. See the plug called X=23?????? Close to the ignition switch??? Its really located about six inches below the fuse box in the engine bay. Is it shorted out??? I doubt it. But happened to me once. Kills the input to the ignition switch which kills the start circuit.

The alternator will work without the two wire plug on the back of the alternator(at least it does on my 87. I had it broken for over a year). I think that part of that two wire circuit is for exitation of the alternator and the other for the ground input to the relay in the CPU that causes the idiot lights to light up.

In other words..........I don't know why your alternator went **** up. I'd have to wing the wires out like your gonna have to .

kbrown211

well see the whole thing is my car will run and it starts with no problem and all the accessories work, its just that the altenator will not charge the battery, also by the way my car is a 88 gtu with a t2 swap from a 87. but i will check the wire you are talking about in the morning

cbrock

iTrader: (1)

Have you even taken the battery to autozone or something of the like to have the battery tested??? If you run an alternator with no battery you WILL blow the diodes. Check your ground on the battery too.

kbrown211

yeah i had it tested and they said it was good, also i just put my multi-meter on it and it was at 11.9 volts

HAILERS

With the car turned off, put your meter on the big wire on the alternator. Does it read 12v AT the alternator???? I thought that would be a good way to tell if that large black wire is/is not broken b/t the alternator and the 80 amp fuse.

I look at the first schematic I attached, and see the wire runs to a splice, and splits off from there going to the ignition and to the 80 amp fuse which in turn feeds the battery. I figure its possible for the wire to be broken at the splice area, but the car to still run and start because the wire b/t the battery and ignition would still be intact.

So, check for 12v AT the alternators big wire.

kbrown211

yeah i checked that wire and it gets the same exact voltage as the battery, i also wiggled around the harness to see if it had a short, but it was good, also i took the altenator to get it tested again he brought out a new one also and in the box it had a note that said the the altenator will not work if it is not grounded to this screw. (little screw on the back of the alt next voltage regulator. so he gave me the old one back and told me to run a ground wire to it and see if it works, but it might be to late since it was never hooked up when i started the car.

HAILERS

Might work. Never can tell. I've never seen one of those type alternators. Good luck.

kbrown211

well it looks the same as the stock altenator, if you look on back of yours you will see a little hole that is threaded for a srew, but i think he was just pulling my chain my car already has about 4 or 5 large ground wires in the engine bay. so difference will this little make on back of the alt

HAILERS

Sounds like a losin deal to me. I've never installed a little screw and ground on any RX I've owned. I'll take a look in the morning at mine and see if there's anything like that on mine. Might be there and I've never noticed. Heck, ship me that alternator and I'll see if it'll work on my car!

kbrown211

well i took off the negative battery cable and ran a test between that cable and the negative battery post and to my suprise there is voltage there 12.5, so i hook up my test light and it stays on and i jiggle the wires to see if there is a short somewhere and i found nothing, but when i tested the fuses in the engine bay all where good until i pulled out the one that says 60 btn, so now i need to find out what that controls as it looks like it is the problem to my short, i put in a new fuse and the light still stayed on.

HAILERS

The 60 amp fuse feeds: The light switch
The heater and a/c

HAILERS

The 60 amp fuse feeds: The light switch
The heater and a/c
The stop lights and horn
The turn and hazard flash
The cargo room lite, courtesy lights, interior and spot lights, audio system and power antenna, seat belt warning buzzer ignition key reminder buzzer, door lock cylinder, egi and emission contro system , theft deterrent

You mean that fuse is blown and no other fuse is blown. Huh. Look again in the interior fuse box.

HAILERS

I wouldn't worry about the taking of the neg terminal off and putting a meter inbetween. I just measured the amperage and it was pulling .01milliamp. Not to worry.

I did see 12 plus volts. So I pulled the BTN and the voltage dropped to 4.6. So I put the BTN back in and looked to see how much amperage was being pulled. See above figure. Negligable.

kbrown211

ok i'm gonna check the interior fuse box again for blown fuses

kbrown211

well i just check the other fuses inside the car and i left the test light on and once i puuled the room fuse it went off so i gotta figure out whats up with that fuse