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Discussion Starter #1
Last week, the volt meter was runnin low so I replaced the alternator. Alternator has a built-in volt regulator so I figured it'd be one of the two. After replacing it, still nothing.

Had it towed to a shop where they traced it back to the alternator. Reassured them it was new and after checking all connections/wiring, indicator line, under dash, still not charging the battery. :banghead

We're stumped...any ideas?

Wiring harness from alt to batt?

Hate to part it out over something like this, but I'm runnning out of options and would dread how much or how long it'd take a Ford dealership to figure it out.
 

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Premium Member
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you can just upgrade to a 3g and forget about it.

but really a shop could not figure it out, that would be the last time I ever took something to them.
 

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Did you take a multimeter and check to make sure it positively isn't charging? Just because the alternator is new doesn;t mean its good. Have it bench tested. Like said above. Find a new shop.
 

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Driving Stuff Henry Built
-90 xlt, 351w, e4od, man 1356, 3.55, sag, warn hubs, 35s. -73, 400, np435, d20j twin, 35s
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Mine had charging issues when I bought it. It was an ebay deal that involved a weekend turnaround trip from LA to Utah & back. Without really checking it out, :brownbag I replaced the alternator on the road, without success. It turned out to be a bad ground cable from the battery. More precisely, a bad section near the block. It's worth a check.
 

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Satyr of the Midwest
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:stupid

Yes, make certain your cables and especially ground connection is sound, although theoretically you should also have a starting problem if the battery cables themselves are the fault....

Usually problems like this can be attributed to a bad fusible link, stator pigtail connector, or regulator connector. All that's necessary to check them is a DVOM. In fact, you should be able to figure out what's wrong with a simple DVOM and a few voltage checks.


you can just upgrade to a 3g and forget about it.
1993+ already has a 3G alternator as factory equipment. :thumbup

One can install a 130A model to replace the 95A model, if one so chooses. However, one shouldn't need it for about 99% of the applications out there.

but really a shop could not figure it out, that would be the last time I ever took something to them.
Yeah, I'm with you on that one. I can't believe there are shops still out there that can't hire mechanics and/or techs to figure this stuff out. It's as if it's not a R&R operation, they go into full-idiot mode. That or they work on gm stuff all the time (in which case they're probably too busy to learn anything else :haha).

Buy a Haynes manual, and follow the diagnostic procedures therein.
 

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had that issue with a buddys pickup... check the grounds... run a wire from the alt. mounting bolt to the batt.

I definetly agree.. find a new shop...


"when all else fails, use more duct tape!"
 

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My stock voltage gauge reads low to. only reads 12v while running. Which I know is not correct. Check the voltage at the battery whiles its running. If its 14 its fine. Dont trust factory gauges completely.
 

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Last week, the volt meter was runnin low so I replaced the alternator. Alternator has a built-in volt regulator so I figured it'd be one of the two. After replacing it, still nothing.

Had it towed to a shop where they traced it back to the alternator. Reassured them it was new and after checking all connections/wiring, indicator line, under dash, still not charging the battery. :banghead

We're stumped...any ideas?

Wiring harness from alt to batt?

Hate to part it out over something like this, but I'm runnning out of options and would dread how much or how long it'd take a Ford dealership to figure it out.
Charging line should have 12V with ignition on or off
Make sure connector is clean, or just get a 4ga or larger battery cable and connect it directly to the positive terminal on the battery or the starter solenoid.

The exciter line (goes in to the side of the alternator) should have keyed on power

I think that's it, right? That's all I remember doing when I converted mine.

What are your symptoms? How do you know the battery isn't charging?

I thought mine wasn't charging because the volt meter was always in the low range of normal and I had problems starting it. Turns out the gauge is inaccurate and my connector from the starter solenoid to the starter (why would they use a solenoid in the engine compartment to control a low current line to the starter?) was loose and not working every time.
 

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Oh yeah... are you sure the battery is good?
 

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Discussion Starter #10
Positive - batt is good.
Took a volt-meter to the batt, reads about 12V then w/ the truck running it still hangs around 12 when should read around 14.
I'll go take another look at the ground connections and wiring. Solenoid is good cause she'll start right up even when solenoid is jumped manually. But when the rigg uses up all of the batt, she dies.
 

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AKA: Butthead
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You would consider parting your truck out over this ???
Yeah, for the lack of knowing how to use a meter. ;)

A weak battery can read lower than 14 when rev-ed, because it's
"soaking up" so much charge. BTSeenT with diesel pickups mostly.
Last one would only raise the voltage about 0.2v. (~'05? F350)

Picking at you about the "parting out" comment was kinda fun but
way-more troubling is your knowing-for-sure your battery is good. :/
That's no way to find trouble. :/

->the battery testers are a gimmick<-

Swap in another "known to be good" battery.
(if you did that already, you should have said so)

And don't just "look" at the connections, check for a -voltage
drop- across them first then take 'em off and clean 'em anyway.

Just think about how much easier all this hands-on stuff will be
than wading-through the replies to your Craig's List ad? ;)

Alvin in AZ
 

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As previously stated, check your ground wires and all connections. If you bought a rebuilt alt. it can be bad from the box. Those battery testers are not always correct, find a good battery as previously stated and swap it in. If no luck and all connections good, and alt was good from box but battery was bad, than you could of burned up the alt. esp if it was rebuilt.

Check every connection and re-ground. Get a known good battery and swap out the alt. Go from there.
 

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Did you plug in that tiny one wire plug that everyone forgets to plug in?
Since you brought it up what exactly does that white wire do? I just changed the plug out on my alt. and the new plug didn't have that extra plug so I reused the old one but that wire is kinda loose in the plug.
 

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Formerly vt89gtvert
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Justg my $.02 but just because the alt is new, doesn't mean that it is good. I had this happen to me twice on my mustang before I bought a PA performance alt.
 

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Satyr of the Midwest
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have you tried unplugging the battery after the engine is started? if the motor dies, you know the alt isnt working. if it still runs then its fine
DO NOT DO THIS.
 

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that wire runs to the dash and lights up the Batt light when you start if the Blub is blown no charge if the wire is bad, No charge, if you swap in the wrong year dash No charge.


NEVER EVER remove a battery from a running system,1st you can total screw your truck computer if not careful, 2nd all it takes is that hot wire to just tap some metal and Boom alt's blown along with some wirring I can assure you.
 
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