Battery light. New alternator 12v
 

I'm not sure when my battery light popped up but i have to charge my batteries every 5 days.. I went on a drive to go ride Dirtbikes and on the way there I noticed my stereo would shut off at random and my volt gauge was all the way low. I got there, rode and had to jump the truck to start it to get home, the batteries did not charge and I ended up driving with no lights no stereo nothing. In the dark all the way home. Pretty scary

I figured it has to be the alternator, I checked my old one and it was 11.5v at idle so sweet bought a new one, installed it, started after cranking for a few seconds. Got 10.1v and this is directly off the alternator. I got a voltage regulator and after cranking a few seconds to start I got 9.5v now. I charged my batteries and I got 12.3v. At this point I believe it has to be my batteries right? But why would batteries make my alternator not put out the right voltage.

Again. I'm reading alternator voltage directly on the alternator

It's not something uncommon, and once the acid in the battery, and the plate break down enough, you won't be getting the charge you need. Also had it happen where mine was so worn down, it reversed the polarity of the terminals, was an adventure replacing every fuse/fuseable link

So just get some batteries and it will work? I'm hoping it was just some fuse and I didn't have to spend $400 on batteries

I would try batteries, since they have such a large draw on them with the glowplugs, and cranking over such a large engine, that they will fail quite easily

Bought new batteries and swapped alternator to a new one again and it's 12.4v

Glad to hear it, these lead batteries are only meant to last 2-4 years at the max (unless you know how to clean them and condition)

Okay... Getting 10v today off my third alternator. Suspecting something else there's no way my alternator could "go bad" then get two faulty alternators. I'm guessing the 12.4 I was getting was from my new batteries.

So you are still having this voltage issue again, or you tested the alt. out of the truck

Not yet

Voltage regulators are a major pain on these trucks .. i blow one every winter about a month into the cold season .... not really sure whay that seems to happen ... BUT its like clock work .. i keep a spare in glove box ...

Check the field wire from the regulator ( exciter wire ) and check the realy wire ( shold be giving the regulator the voltage @ batteries ) ..:humm:

Have a new voltage regulator in

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Can I get a picture of the voltage regulators and the colors of the wires that come out? Mine doesn't have a plug. Just 4 wires that have connectors. Maybe I put them on the wrong way?

.....Make sure all (ALL) batt electrical connections and grounds are clean...shiney. I found one of my cables clamp end was corroded under the plastic cover and between all the wire. Remember when lead corrodes it becomes gray and darkens to charcoal. This cable or cable end corrosion at a connection requires additional amps to cause the current to flow thru the corrosion to charge the batteries. When I lived along the Texas gulf coast, I cleaned all lead connections every 4-5 months. Some of the newer connectors are steel and don't completely encase the battery lug, but have two thin, 1/8th in or so, bands that tighten around the lug, which even leaves less connector and more open corrosive area to contend with......and they as you know are very difficult to adequately tighten. I've replced them with brass couplers. By doingn all he above, I've not had a ded battery in over two years. KNOCK on WOOD!!!

also using a good battery protection spray of simply grease ... i use grease on the off road stuff and spray on cars and pickups that are not 4x4's..:tu:

I will post some pics in my build page this week ... will try tomorrow night ... been busy ..

Maybe Dortiz might be able to get to it before me ..:tu:

Even on new batteries I would need that?

Yes, recommend that you spray the connections on all batteries, new and old, I've had several new batteries completely corrode the terminal connector within a week on separate occasions, the spray eliminated all corrosion on my batteries every time, so all I can say it do it no matter how long the battery.

let me go outside and I'll grab a picture of mine

Located on passenger fender, behind the battery, just below the starter relay :humm:

Hah looks like I wired it backwards... Soo I wired it like yours and I got 24v from the alternator? Woah? Is that right?

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Getting 13.5v now thank you!

sorry for the late reply! I don't remember how I wired mine in, but I had to rewire it from the PO, glad to help. Anytime you have a question, feel free to ask away. :rocking:

i have had a issue changed batteries and alt and still no charge it was a resistor in the dash cluster that tells the alt to charge i changed the resistor after spending over 500 on repaires and it then charged great but i also do not have the external reg