Alternator question
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Alternator question
I've known for a while that my alternator would be kicking the bucket. Pretty sure it's done now, or close. Just recently the battery light turned on, and my question is this: Ever since the light came on it has been running worse and worse. At idle it is stumbling like crazy, and it just doesn't seem to be driving right in general. Could that be linked to the alternator in these trucks? The weird thing is that I haven't had any issues with the battery not charging.
Logistics Pro
Joined: Mar 2005
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From: Mexico, Missouri
Yes, very much so. If the alternator is dipping on output, then the battery is only gonna last so long. Sensors get a signal reference and if they don't get good voltage supplied, will in turn throw the circuits out of whack. Usually TPS, O2, EVP sensors show the greater amount as they control fuel trim at Idle and cruising speed.
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Thanks for the reply, I actually just removed it and took it to get bench tested. It passed three tests. Only conclusion I can come up with now is a loose connection somewhere. With the lights on in gear vehicle stopped with the brake depressed, the battery gauge dips really low and all the lights dim. It'll almost stall the truck sometimes with the power steering working simultaneously.
The battery light came on a couple days after I sprayed off the engine compartment. I'm Going to look at the connections now.
The battery light came on a couple days after I sprayed off the engine compartment. I'm Going to look at the connections now.
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Checked for the better part of an hour looking up and down all the wiring. Looks pretty good, except for all the vacuum and unplugged connectors that the previous owner must have done. There are TONS of plugs not plugged into anything, and even more vacuum lines plugged off or leading to nothing. I know he disconnected all of the emissions equipment, but this is bugging me not knowing what is what and what should be plugged in.
However, while I was working on it maybe I bumped into something for the better. The battery light hasn't come back on yet and the gauge doesn't seem to be dropping when the lights are on. Maybe it's because I had the battery unplugged for a while and it just reset things. The idle is frustrating though. between 700-1200 RPM it runs rough as hell, then it clears up quick as could be immediately following about 1200.
However, while I was working on it maybe I bumped into something for the better. The battery light hasn't come back on yet and the gauge doesn't seem to be dropping when the lights are on. Maybe it's because I had the battery unplugged for a while and it just reset things. The idle is frustrating though. between 700-1200 RPM it runs rough as hell, then it clears up quick as could be immediately following about 1200.
Post Fiend
Joined: Apr 2004
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From: Lafayette, IN
A rough idle, on the cusp of dying, can cause the battery light to flicker and the voltmeter to fluctuate. Pull your codes even if the engine light isn't on. Fuel Injection Technical Library has a write-up on how to do it if you're not familiar.
Jason
Jason
The Southernmost Mod
Joined: Dec 2004
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From: Caracas, Venezuela
Before anything else, try the easier solutions: Clean the battery posts and tighten the clamps up. If that doesn't solve the problem you might want to check the brushes inside the alternator, I bought and replaced these for like $5 not so long ago and that solved my alternator problem with the battery light and all... Of course, check/clean all the connections.
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Logistics Pro
Joined: Mar 2005
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From: Mexico, Missouri
I didn't ask this and it wasn't mentioned earlier in the first post. What year and engine are you addressing problems? The I-6 has a ground from the neg. post to the frame then to the starter. Its held in place at the frame with a conduit like clamp. It is exposed wire and very well could have some corrosion in it. I'm not positive for higher C.I.D. motors with regards to that same clamp.
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