Alternator?
Alternator? 98' fbody ls1(99' harness/pcm) in a 80' caprice, everything is connected and motor is running fine but alternator is not charging
. Took the alternator out and had it rebuilt believing that to be the problem but it still isn't charging. Anyone know how it should be wired?
. Took the alternator out and had it rebuilt believing that to be the problem but it still isn't charging. Anyone know how it should be wired? 
Teching In
Joined: Feb 2008
Posts: 31
Likes: 0
From: Long Island N.Y.
go to www.hotrodlane.com street&performance they have a wiring diagram for alts just choose your style
Teching In
Joined: Mar 2007
Posts: 39
Likes: 0
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
If its a 99 PCM/harness with a 98 f-bod alt you should be charging fine right now.
Turn the key to on, unplug the weatherpack off the alt and check for voltage, it should have ~9 volts or so. Now wiggle the wire around as you do it. The f-bodies are famous for having the strands of that wire break internally within a couple inches of that connector. The wire looks fine on the outside, but is broken on the inside so the alt will no longer charge.
Turn the key to on, unplug the weatherpack off the alt and check for voltage, it should have ~9 volts or so. Now wiggle the wire around as you do it. The f-bodies are famous for having the strands of that wire break internally within a couple inches of that connector. The wire looks fine on the outside, but is broken on the inside so the alt will no longer charge.
If you still suspect the alternator, take it down to a Autozone, Kragens, etc. or any shop that has the test equipement and have them load test it.
if the alternator checks out and if you suspect the wiring next. Check to voltage a the connector (B terminal), if your not getting a activation voltage, then the PCM is not sending a activation single to the alternator.
You can always try to activate it manually.. with a 12+ input with a light bulb in line to the B Terminal to see if the alternator starts to output a charge ?
Just be carefull, these alternator have been know to burn up easy due to the wrong input activation signal.
if the alternator checks out and if you suspect the wiring next. Check to voltage a the connector (B terminal), if your not getting a activation voltage, then the PCM is not sending a activation single to the alternator.
You can always try to activate it manually.. with a 12+ input with a light bulb in line to the B Terminal to see if the alternator starts to output a charge ?
Just be carefull, these alternator have been know to burn up easy due to the wrong input activation signal.
