If I go with the bulb, do I splice it inline (in AND out) or do I tap in and ground the other side of the light socket?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Alternator Not Charging - FIXED!
- Thread starter nvrenuf
- Start date
bronc3buster842001
1/2 ton status
Splice it in and out..
Oddly, I went to a car show today and saw an older truck with a serpentine belt set up and same alternator. 1 wire going in the plug and 1 wire on the stud. Why can't life always be easy....
I believe there are kits to convert the old 10 SI alternators to a one wire configuration...maybe some for the later ones too?..
Well crap... I've installed the bulb and took the alternator to O'Reilly's and had it checked (showed good, 14+v) but it's still not charging. I also noticed the bulb doesn't flicker with the key cycle (unless it's too dim to see with the shop lights on).
If I disconnect power from the alternator and then reconnect, the first crank will should charging around 14v for 2~3 sec but then quit. From then on, the voltmeter doesn't show charging. It's almost like a breaker is tripping.
Can I check the alternator itself with a handheld voltmeter while it's running?
I'm afraid I have a wiring issue I haven't found.
If I disconnect power from the alternator and then reconnect, the first crank will should charging around 14v for 2~3 sec but then quit. From then on, the voltmeter doesn't show charging. It's almost like a breaker is tripping.
Can I check the alternator itself with a handheld voltmeter while it's running?
I'm afraid I have a wiring issue I haven't found.
Also, can a fusible link show continuity yet still be bad? There a link coming off the stud but my meter beeps saying it's good.
I have seen more than one fusible link that had been partially fried,and only a few good strands still conducted current ,good enough to light up a test lamp,but not deliver enough amps to work under a heavier load..so yeah.I'd say its possible..
Ok, maybe that's part of the problem. Where do I find the size to get another? I don't see it on the diagram I posted.
Or... Should I just get an inline fuse? Again, what size fuse?
Or... Should I just get an inline fuse? Again, what size fuse?
Last edited:
I "think" they used 14 gauge fusible links...at least on older square bodys,thats what my Haynes manual's wiring diagram says...
I found these 2 diagrams on google images ,far as I can tell the two "hot" wires need to have power--one needs a constant hot feed,the other switched by the key,with the lamp for resistance...you can just jump 12V to the keyed hot wire temporarily to see if it'll start charging then,if it does,your not getting power from the ignition switch..
I found these 2 diagrams on google images ,far as I can tell the two "hot" wires need to have power--one needs a constant hot feed,the other switched by the key,with the lamp for resistance...you can just jump 12V to the keyed hot wire temporarily to see if it'll start charging then,if it does,your not getting power from the ignition switch..
Ignore the first diagram showing an external regultaor,that just is showing how to hook a CS130 up to a pre 1972 GM vehicle--I only used that diagram to show which 2 wires on the alternator that need to get 12V..
I posted some info on CS alternators here: https://ck5.com/forums/threads/ques...-and-electric-fans.305889/page-3#post-3260740
There is more than one kind. Some need the resistor/lamp and some don't. The best way to test if it's charging is with a current clamp on the output wire, but a voltmeter also works. If you get 13.x on the output terminal, also measure at the battery. You don't happen to have a battery isolator, do you?
There is more than one kind. Some need the resistor/lamp and some don't. The best way to test if it's charging is with a current clamp on the output wire, but a voltmeter also works. If you get 13.x on the output terminal, also measure at the battery. You don't happen to have a battery isolator, do you?
No isolator. Thanks for the link, checking it now.
I threw a fusible link at it real quick this am but still no charge. Oddly, at start up the in cab gauge (again) briefly showed 14v for about 5 secs (a little longer this time) but then stopped. It's like I'm tripping a breaker inside the alternator.
If I disconnect all power for a little while it will show the brief charging on the first crank but not on subsequent cranks until power is disconnected again.
I've got to leave for a while but I'll play with it more tonight. Lots of info in that last link to study too.
If I disconnect all power for a little while it will show the brief charging on the first crank but not on subsequent cranks until power is disconnected again.
I've got to leave for a while but I'll play with it more tonight. Lots of info in that last link to study too.
454Sub
5/8 ton status
I would wire the resister light bulb into the factory warning light. Then it works like it should anyways, like factory. Plus you can see if your ALT fails when the light comes on while driving. Secondly, why not just run a 6-8ga wire from the positive post of the ALT to the battery, bypass all them and directly charge it with a larger wire.
Nope, cluster is not plugged in. I don't have any of the printed circuit in the truck. Most of my wires to the gauges come straight from the sensors. My volts gauge is just hooked up to power and a ground.
These are my plug.
The wires just go to where ever they did from the factory. I also have a hot wire that comes directly off my battery isolator (for the dual batteries I'm running, it's just getting a constant power) to the post on the back of the alternator, and the factory fusible link is still there. One thing that I messed up when I first did my body swap was I had the fusible link for the starter and alternator mixed up. That didn't let the alternator charge, it also made the turn signals not work IIRC.
These are my plug.
The wires just go to where ever they did from the factory. I also have a hot wire that comes directly off my battery isolator (for the dual batteries I'm running, it's just getting a constant power) to the post on the back of the alternator, and the factory fusible link is still there. One thing that I messed up when I first did my body swap was I had the fusible link for the starter and alternator mixed up. That didn't let the alternator charge, it also made the turn signals not work IIRC.
It's fixed! Sadly, it was the f#%!$&@g alternator the whole time. 
I had previously had O'Reilly's check the alternator and it showed good (I watched the test) but out of frustration I took it back and asked them to exchange it just to rule it out. Well, it's on and it's charging ~13.9v!
I really appreciate every bodies input in this, it was all truly helpful.
I learned a ton doing this, hopefully, the tech here will help others too.
I had previously had O'Reilly's check the alternator and it showed good (I watched the test) but out of frustration I took it back and asked them to exchange it just to rule it out. Well, it's on and it's charging ~13.9v!I really appreciate every bodies input in this, it was all truly helpful.
I learned a ton doing this, hopefully, the tech here will help others too.
