$5 paypal if you can answer this question

[jtbuck92]

I have a 03 4.6L Exploder.

Simple question really- what voltage does the stock alternator put out in order for the dash light to NOT come. As in, what voltage turns off the dash light. It's not a 12v source, already tried that.

Reason for asking is I have an aftermarket alternator and the FLD doesn't output the same voltage as the stock alt. So I need to recreate whatever voltage the stock alt sends to get my dash light to turn off. I have plenty other ways to monitor my voltage.

 

[Turdle]

14.3

or 42 whichever comes first.


Keep your $$$

 

[IZwack]

In the unlikely event that Turdle is wrong, my bet is on 13.8 (only because its half a volt less than his value and I'm half the man that he is)

 

[Turdle]

In the unlikely event that Turdle is wrong, my bet is on 13.8 (only because its half a volt less than his value and I'm half the man that he is)

I think you have that backwards. Silly

 

[jtbuck92]

So I'm actually charging at 15.1 right now. If I get 14.3v to that wire, that should make the dash light go off?

 

[Turdle]

Could you just unscrew the bulb?

 

[jtbuck92]

No, because it also comes up on my info screen on the dash. It tells me, you know, how many miles I have till empty, gas mileage, etc. And it beeps at me. I would rather recreate whatever source I need to in order to make it go off.

 

[storlied]

I only see 15.1 or so on a cold start in cold weather, isn't it bad to have such a high rate of constant voltage? After warm up I usually see 14.7-8.. and with accessories around 13.8 or so. It's odd that it's even coming on for a high voltage situation.. then again I have seen my radar detector tell me Over Volt during electrical issues like trying to charge a battery in freezing temps when things have gone to hell.

I think what this is gonna come down to is anything from 14.9 and lower will be okay for it? You said you tried 12, but if the engine is running.. it would naturally sense a problem due to you Only have 12 volts.. it was thinking you had an alt problem.

Maybe I'm just full of it, idk. Makes sense to me. Anything from 13.7-14.9 is okay.
Anyone?

 

[jtbuck92]

I only see 15.1 or so on a cold start in cold weather, isn't it bad to have such a high rate of constant voltage? After warm up I usually see 14.7-8.. and with accessories around 13.8 or so. It's odd that it's even coming on for a high voltage situation.. then again I have seen my radar detector tell me Over Volt during electrical issues like trying to charge a battery in freezing temps when things have gone to hell.

I think what this is gonna come down to is anything from 14.9 and lower will be okay for it? You said you tried 12, but if the engine is running.. it would naturally sense a problem due to you Only have 12 volts.. it was thinking you had an alt problem.

Maybe I'm just full of it, idk. Makes sense to me. Anything from 13.7-14.9 is okay.
Anyone?

I have a high output alternator (300a), I control what voltage the alt charges at. I have high end audio batteries that will take a 15v charge for a long time, and they actually like it.

When I say 12v, I meant that as I jump a small wire with a 1 amp fuse to the dash light wire (green and something) while the vehicle was running.

My new alt puts out around 3.5-4.5v through the FLD (field) wire, I don't know why. I guess it's just the way it's built, to work at a different voltage. Like I stated previously, I have plenty of monitoring over my alt, and I just want to turn the dash light off. But what doesn't make sense to me is I jumped the dash wire to the bat when I was charging in the low 14's and the dash light was still going nuts.

 

[storlied]

So are you saying that high rate of charge (15v) is going to everything? What you need to do is somehow limit the voltage down a bit to everything but the audio equipment ..

Hmm... your truck is just getting too much voltage. It's probably sensing it through the PCM/ECU even though you're jumping it from the battery.. which (I think) would still be getting that 15v....

I'm no expert on any of this and I'm sleep deprived so.. lemme know if I'm not making any sense.. but this is how I'm seeing it, along with what I said earlier.

(Btw, you don't have to pay anyone here for help, that's what were here for.)

 

[Anime]

Whatever the voltage regulator setting is.

I'd guess that to be 14.6-14.7V on the high end.

If it's charging at 15.1V, the high end audio battery may like it but the rest of the vehicles electrical system might not.

Sounds to me like the voltage regulator on whatever alternator you're using isn't made for the particular vehicle you're using it on, or it's a high end competition level piece and you're trying to use it for regular duty.

You might "fool" the system by just getting 13.8-14.9V to the warning light, but I'd be more concerned about the rest of the electrical stuff running at higher voltages than it's designed to see.

I'd say regulate the alternator voltage back to stock levels, and work on isolating the high end audio batteries so they can charge at the 15-15.1V seperate from the rest of the electricals if you still want them to charge at that voltage.

 

[storlied]

What he said. ^^ That's exactly what I was trying to say.. haha.. long day.. Happy Thanksgiving everyone, time for a nap! I'm stuffed.

 

[jtbuck92]

I am confident in my vehicle's ability to hold up at that voltage. I've done this a couple of times lol.

See the thing that I don't understand is that when I hook it up the dash wire to the fld on the new regulator, the dash light does off, then comes back on, then goes off, then comes on, etc...

I've tried different charging voltages as well and all of it leads to the same results.

 

[storlied]

It'll hold up, it's just not gonna like it. There's always a Possible Risk you could fry something, either way.. I'm sure your PCM/ECU is picking up on it and reporting it to you.

 

[Radioace318]

I have a 03 4.6L Exploder.

Simple question really- what voltage does the stock alternator put out in order for the dash light to NOT come. As in, what voltage turns off the dash light. It's not a 12v source, already tried that.

Reason for asking is I have an aftermarket alternator and the FLD doesn't output the same voltage as the stock alt. So I need to recreate whatever voltage the stock alt sends to get my dash light to turn off. I have plenty other ways to monitor my voltage.

How about a variable resistor to the B+ supply to your warning light circuit. Then you may adjust until your light is happy.


Just a thought.

Cheers
Rick

 

[Anime]

The system probably doesn't work by the light being off or on based on the voltage it's getting, but by the voltage the computer reads the system getting.

It will "handle" 15+ volts, the same way it will "handle" being driven at 150+ MPH...maybe it'll do it for awhile, but it'll have a greatly reduced lifespan and you'll wind up replacing a lot of stuff. Frying stuff and replacing things that can be hard to get like the computer is not fun.

Live and learn.

 

[jtbuck92]

How about a variable resistor to the B+ supply to your warning light circuit. Then you may adjust until your light is happy.


Just a thought.

Cheers
Rick

Yes, indeed. This was my original thought.

 

[jtbuck92]

The system probably doesn't work by the light being off or on based on the voltage it's getting, but by the voltage the computer reads the system getting.

It will "handle" 15+ volts, the same way it will "handle" being driven at 150+ MPH...maybe it'll do it for awhile, but it'll have a greatly reduced lifespan and you'll wind up replacing a lot of stuff. Frying stuff and replacing things that can be hard to get like the computer is not fun.

Live and learn.

I don't want to sound like an ass here, but I work on vehicles electrical systems everyday. I'm not worried about my vehicle's ability to take the voltage. Actually it doesn't really bother me at all.

The only concern/issue I want to address here ITT is that I want to turn the dash light off. Sending the right voltage to that dash wire should turn the dash light off.

 

[jtbuck92]

So would the voltage not being at exactly 14.3 cause the light to come on? I mean what about like 14.6.

 

[Joe Dirt]

I'll bet $1, Bob...

Wait- wrong game.