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98 1 wire alternator?

8K views 17 replies 5 participants last post by  gmcxt 
#1 ·
Have a 98 4.3 vortEc and it constantly overcharges, had two alternators and lots of problems with them. Is there a company that makes a 1 wire for this motor, or is there a way to convert mine to 1 wire
 
#3 ·
Basically I keep getting an overcharging condition from my alternator, I tried changing the alternator and no luck. Also my inline light bulb (resistor) won't turn on anymore...anyone have any thoughts (the light is not bad)
 
#4 ·
there is usually small wire (not the charging wire) one wire that hooks from the battery back to the alternator. the regulator uses the voltage on this wire to set charging system voltage. it sounds to me like you have high resistance on this wire, so in turn the alternator is cranking up the charging system voltage because it thinks the voltage at the battery is lower than it really is. i would look into this before spending a bunch of time and money trying to make something else work.
 
#5 ·
I'm not familiar with this wire. There is the hot wire that goes from rear alt post to positive bat post, and there is the 12v key on wire that plugs into the small pigtail on the side of the alternator that has the light bulb for resistance on it. Can u elaborate where this wire is supposed to be...picture?
 
#6 · (Edited)
Basically I keep getting an overcharging condition from my alternator, I tried changing the alternator and no luck. Also my inline light bulb (resistor) won't turn on anymore...anyone have any thoughts (the light is not bad)
Is the bulb good? Does it turn on when turn the key ON (engine off)?
Check the continuity of the wire if its dead. One side of the bulb should see switched battery voltage, the other should have continuity back to the connection point on the alternator (meaure resistance of the wire using a long jumper wire, or measure the voltage at the alternator side on this wire (key on, engine off) both connected and disconnected).

Which alternator do you have on your truck? Snap a picture of the backside if you don't know.

Basics on the alternator, the large post is your output, that goes to the battery +ve. Another wire is a sense wire, that tells the alternator what voltage is in the system. On older GM 10SI/12SI apps, that wire just loops back to the output wire. And then theres the wire that goes back to the idiot light. Depending on what alternator you have, this may (CS series for instance) or may not be important (SI series).

Alex.
 
#7 ·
yes the bulb is good, i hooked a ground wire to it and it fired right up...it does not turn on when the ignition is on but the vehicle is not...it used too though, i know it has somethign to do with my overcharging issue cause once it stopped turning on i started having the problem.

there are two wires coming off of the rear post of the alternator in the picture, they are both going to the battery positive. all these problems started when that wire broke, so i replaced it with two (backup wire) but the problem persisted. I have since tried a new alternator and still have the same problems and i had them both tested and they both passed three times each...so its gotta be somethign simple.

I am goign to try to run a wire to the starter from the rear post to see if that helps, if i do that i should get rid of the wires running to hte battery?


 
#8 ·
Yes the bulb is good, i hooked a ground wire to it and it fired right up...it does not turn on when the ignition is on but the vehicle is not...it used too though, i know it has somethign to do with my overcharging issue cause once it stopped turning on i started having the problem.
You got a broken wire somewhere in that circuit. Do what I suggested, and go to the alternator plug (the 4 wire plug. Disconnect it, and measure for voltage at the appropriate pin (look at this pic for pin assignments: http://www.hotrodlane.cc/ONLINETECH/CS130DREG.html ) with the plug disconnected and the key on. You should measure voltage in that condition.

there are two wires coming off of the rear post of the alternator in the picture, they are both going to the battery positive. all these problems started when that wire broke, so i replaced it with two (backup wire) but the
Next time use 4 guage, run it to the starter if you wish, or run it to the battery via a 200amp fuse (if theres a short in the alternator, you'll burn your rig down if there is no fuse or fusable link (the original wires running to the starter used fusable links).

problem persisted. I have since tried a new alternator and still have the same problems and i had them both tested and they both passed three times each...so its gotta be somethign simple.
I do have to ask since I don't see the plug in the photo, but you do have something plugged into that connector thats "behind" the inline fuse in your pic? If theres no Sense connected the alternator isn;t going to do anything. Check inside the connector end as well for corrosion. AND again, use a meter and test what is there, visual alone is not good enough.

Alex.
 
#9 · (Edited)
I'll check everything u mentioned. If nothing works I'm just going to Pull all the wires associated with charging and start over clean. As for something plugged into the space on the back of the alternator, I have it unplugged but it's the big white blOb in the bottom right corner of the picture
 
#10 ·
i would not run those two smaller wires, your just asking for a fire, as if one gets shorted they cant draw enough amps to blow the fuse. a 4 gage wire hooked to a 200 amp fuse should do. i went with car stereo amplifier hookup wire and the matching connectors to make a clean setup. the connector is pretty important, and solder it to the end if you can, if there is any resistance in the end (usually the problem with crimp connections once the get a little corroded) it can heat up the connection and make all sorts of problems. i have seen the aftermath of setups like you made when they get towed in not charging.
 
#12 ·
I soldered up an 8 gauge wire (largest I had) and it seems to be running great again...the light still is t coming on before it fires up but it's running staying at 14.2v after I drove it around, and that was with the electric fan lights and rock lights on...
 
#14 ·
My rig def doesn't see much road. But ya it's working great, thanks everyone for your help. It's loaded on the trailer right now, headin up the mountain after work tomorrow
 
#17 ·
turns out i am not in good shape...my voltmeter was bad. I had a spare and checked them side by side and it is off a couple volts (probably due to being dropped) so i had a union electrician buddy of mine stop by and we checked my back up meter to his 800.00 meter and they were spot on...so i don't have a functioning alternator still. I was out wheeling this weekend and the battery stopped cranking after three or four hours. So i am back to this problem:

as far as i'm concerned as long as that light bulb does not turn on with the "key on" power to it then there is something wrong...Anyone have a clue why the light wouldnt be on? I am definetly getting power to that light bulb and the light is still good. If the voltage regulator was bad would that cause the light not to turn on...
 
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