nar_dog7

Please any and all opinions. So i have only had the car about three weeks, for the first week and a half it was fine everything ran fine. Then one day on my way home it started to stutter and try to die. I turned off the rear defrost, the cd player, and the heater. i got the car home and it died i jump started it and it ran fine until i disconnected the jumper cables then it died, the battery had no juice. So i had the starter, the alternator , and the battery which is brand new tested just to be safe. then i checked all the wires that are involved in the starting system i checked them for continuity and ohms. I cleaned the ends of them with a wire brush and put them back on. Then i took the battery in and had it tested, it tested fine. So they charged it for me i took it home put it in the car fired right up and everything seamed fine. My father came over and tested it it had 12.4 volts he then checked it for amperage i do not know what that read, but he said it was charging so everything was fin. Today i drove it to have the exhaust fixed a total drive time off around about a hour. When i got to the road i live on which is very bumpy it started to stuter and died again.any ideas i do not know a whole lot please if you have any ideas just tell me where to start. first thing tomarow i am going to take the alternator in and have it tested 4 or 5 times again. Last time they tested it once and someone told me to have it tested several times.

90 camaro cj

if it was at 12.4v when running it wasnt charging, about 14.0v is what my cars all show when running. ~12.7v is a fully charged battery. if you cant get it to show over 13.5 or so when idling with nothing on just running it makes me think the alt. is bad unless you have a lose concetion somewhere best of luck, but if it was me id check all main conections and if it didnt work then id be looking at getting an alt.

CamKid1992

sounds to me there is no connection between your alt. and your bat. sure it will run when the battery is charged. so it dies from everything running off of it. you could have a broken cable bad connection or on the alt. i have seen them place a rubber insolater on the connector to protect it from debris. check all that. just my

jeff_blake

iTrader: (1)

yea i agree with cj, i myself at an autoparts store. i would say the alternator, or loose connections as well. most common problems we run into. alternators for thirdgens are fairly cheap, and easy fix.

ASE doc

Check for voltage to all the wires on the alternator. With key on, engine off all the wires at the back of the unit should have power. If the tan wire is dead, check the fan/FP fuse in the underdash fuse panel. If all wires show power, have the alternator checked again. It may have bad brushes and work intermittently.

nar_dog7

Hey thanks for all the responses this is driving me so crazy i cant sleep. I bought a new alternater today that did not fix the probleom I am just throwing money at it now.
ASE doc I checked all three wires that plug into the alternater two of them had power the one to the battery and the one to the starter were fine. The liitle tiny tan one that goes to the fuse panel labeled fan like you said had little to no power .1-.3v. What does it do? a guy at my local oreilly's said it went to the battery gauge. How much power should that tiny wire have? Sorry if this sounds stupid but when it comes to mechanics im not to bright, but trying very hard to learn. Thanks for your help

ASE doc

Thats the activation wire from the ignition circuit. It basically turns the alternator on when you turn the key on. Check the FP/fan fuse in the in dash fuse panel. If the fuse blows repeatedly, check for bad fuel pump or cooling fan relays. The fuse provides ignition power to the alternator and the primary coils of the fuel pump and fan relays.

88sporty

ive run into the same problem as you have, and as well im searching for an answer. except it gets more complex, as i am unsure of if i am missing a wire. i got a car from a guy before i noticed that he had totally stripped the wiring harness (the pcm end of it anyway) and i only have the wire plug to the alternator, with two wires, which one goes to the post on the alternator, so my question is, am i missing a direct connect to the battery? nar had mentioned there were three wires. also just to clarify, the alt is new as is the battery, thank you for any help

nar_dog7

well sporty i have ben through my charging system forwards and back and i just finished fixing it. Thanks to the help of everyone above. Im not sure about your car but my 91 has three wires one from alt. to the battery one from alt to starter and another from alt to fuse block. Is there anything else wrong with your car does you ac work, does you electric fans work if you have electric fans. The reason i ask is cause when finally fixed my car it was because my fuse block was not not getting power to 3 fuses the fan, heater/ AC, and another which is not used those three fuses got there power from a orange wire that clips under the dash to the steering column. If i were you i would start at the begining... the fuse block test your wires from the begining make sure the fan fuse has power and start working down the wire probing the wires with your dvm. I do not know a whole lot but i was able to track down my wires and figure it out. So if you have any questions about what i did to figure it out just ask me. hope i can help i know wiring can be frustrating.

AND ONCE MORE THANKS ALL OF YOU ESPECIALLY ASE doc.

ASE doc

I've seen GM alternators wired that way. It's different from most 3rd gens I'm familiar with and I don't have access to wiring diagrams to diagnose it for you by schematic right now. Start by testing for power at the alternator post with the engine off. This verifies that there isn't a blown fuse link in that circuit. Then test for power on the other wire in the alt plug with the key on. That wire probably goes to the BATT indicator light. Does your BATT indicator light up with the key on? If not, check the gauges fuse. Check all fuses in the in dash fuse panel while your at it.

88sporty

i've checked fuses before and only had one blown which i replaced, since then i didnt have any of them blown that i have caught. i dont believe that i have a battery light on my dash since i have the gauge, but i also have no pcm computer in the car it is a carb swap with only a mech fp. im going to start with testing from the alt and the fuse block. thank you for the ideas!

1BADL98

If it get's too frustrating just buy yourself a one-wire replacement. You can get them from Jeg's for around $160 for a 105amp or around $200 for a 140amp if your running extra electrical stuff.You may could even find a used one cheaper. Just my

Six_Shooter

iTrader: (2)

1-wire alternators are the worst idea for a street car.

Most won't turn on until well above idle RPM, and then will shut off again when returning to idle.

89/91rs

make sure your leads connecting to your battery are tight....if you can shake them with relative ease then they are too loose. I had your exact problem, then i cleaned off the tips of the leads, and tightened them as hard as i could, and havnt had any trouble after that.

ASE doc

Have you tested for power at all wires to the alternator? Test with the key on. If the large wire doesn't have power, suspect a broken fuse link at the battery. I can't find a wiring diagram for your charging system anywhere. It's frustrating not having diagrams here on TGO. I have the Helms Electrical Diagnosis manual for my 87 and would gladly scan the entire thing and upload it for everyone's use. If one person for each year did the same, we would have an excellent resource for all members.

I can only imagine that your alternator receives its activation signal through the gauge circuit. That's why you need to verify power to both wires at the alternator with the key on.