|
|
|
Charging system failure- can't figure out
|
|
|
| |
|
|
rmcminn
New User
Dec 7, 2013, 9:26 PM
Post #1 of 3
(1250 views)
|
|
Charging system failure- can't figure out
|
Sign In
|
|
Hi. I have a 2004 Malibu Maxx with 100k mi. It has the 3.5 V6 and the problem I am having is with the charging system. I bought the car after it had set for a few months and had to do a few things to it like a new battery etc. The battery is new and good but the battery light on the dash was on from the start so I had the altenator checked and it checked out good, too. Still, after a few starts and driving a bit the battery will run down and the car will fail to operate. I have checked the fuses including the 80 amp in-line thing going into the fuse/relay box next to the battery. I started it and then disconnected the positive post on the battery and it died. I cannot do any more with my knowledge. Any help out there?
|
|
| |
|
|
Tom Greenleaf
Ultimate Carjunky
/ Moderator
Dec 7, 2013, 10:52 PM
Post #2 of 3
(1234 views)
|
|
Re: Charging system failure- can't figure out
|
Sign In
|
|
Quote">>I started it and then disconnected the positive post on the battery and it died.<<"
Ooops! That's a great way to toast expensive things like the ECM! NEVER do that as now this is going to be a project. Just responded to a PM on this not knowing that part of testing.
OP = original poster, that test dates back to the 50s into early 60's and for generators not so great then and destructive now! Alternators require power from battery vs generators that didn't. Now all prior testing needs to be redone with test lights and voltmeter at a minimum.
Look up that is flawed sometimes shows alternator is regulated outside of alternator, not a separate part so in the ECM (computer.) I see it tested OK off car now, check plugs in connections and wait for more suggestions but expect nasty damage now,
T
|
|
| |
|
|
Discretesignals
Ultimate Carjunky
/ Moderator
Dec 8, 2013, 6:34 AM
Post #3 of 3
(1221 views)
|
|
Re: Charging system failure- can't figure out
|
Sign In
|
|
Tom's right to never disconnect a battery cable while the engine is running on computer controlled vehicles. If the alternator was functioning, disconnecting a battery cable could cause a voltage spike to go through the electrical system. Most solid state device don't hold up to extremely large spikes. Even though most modules have some type of surge protection are you willing to find out if it is working properly?
Your vehicle has an alternator that has an internal regulator, but the field is turned on and off by the PCM (powertrain control module). First thing you need to do is test for charging system voltage on the back of the alternator at the battery lug, with the engine running, using a volt meter. Charging system voltage should be around 13.8 to 14.0 volts.
If you don't know how to troubleshoot electrical systems, suggest you have it towed to your local mechanic.
Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
|
|
| |
|
| | |
|
Auto Repair Home
SEARCH
WHO'S 
LOG 
Subaru Forester white smoke at start up
1989 toyota pickup 3.0 crank no start
