Getting 19 volts out of old and new Alternator(s)

[POPPAWS BRONCO]

Well if anyone here follows my post you would know nothing comes easy for me and my 77. So my FAST EFI system told me my battery is putting out at times 19 volts while engine is running. Took Alt to local Auto Zone had it tested and it failed, purchased new one and it is putting out 19 volts too. Is that my luck just getting a bad Alt or am I missing something. I removed a lot of wires from old system I didn't need when installing the FAST system. When I turn lights on the volts meter drops. Is the system needing to have more volts pulled from it? I don't have a radio installed either. So really nothing is pulled except what it takes to run the Bronco.

Side note, I think my troublesome Bronco needs a name.


Hey!!! Let me hold a dollar I'm in the middle of a restore here!

 

[blubuckaroo]

You have a regulator problem. Voltage that high will cook your battery.
Is it a factory type alternator or a newer one with an integrated regulator?

 

[POPPAWS BRONCO]

The one that came off was pretty cruddy looking the one that I put one was the one that pulled up I didn't know to look into any specs. I did watch the test at AZ and the regulator was what failed on the old one. So is the regulator built in or separate unit. Here is the part number and some screen shots of what I got. I'm running a yellow top optima battery

Hey!!! Let me hold a dollar I'm in the middle of a restore here!

 

[Steve83]

You should post pics of your Bronco, and the alt on it. We need to see the BACK of the alt to know what type it is. Click these & read the captions:

. .

In any case, you should stay OUT of the zone.

 

[AxlesUp]

the zone is a great place if you really like replacing parts. like the same parts over and over..........

that pic says its externally regulated. so you either need a new regulator or need to wire it in or both ooooorrrrrr you could just get a modern alternator like the 3g or 4g ford alternators and be done with it.

19volts will cook all your new goodies and all your old stuff too.

i have had excellent luck with powermaster alternators over the years.

 

[jtboarder]

19v will do a lot more than cook the battery. I had a voltage regulator go bad on my F150 crusing at 2000rpm (voltage will rise with rpms), batteries boiled over, before i could catch it the headlights, wipers, window motors, door locks, and instrument cluster all fried. All without a single fuse blown. Im not great with the relationship between voltage and amperage, but dont play games with it if you have anything electrical of value hooked up to it while its producing that voltage.

 

[ncr1975]

alt problems

The alternator you describe is externally regulated so it should only respond to what the voltage regulator tells it to do. Did you have your voltage regulator (VR) tested off the vehicle? If the VR and the alternator test good then you have a communication problem between the Alt, the VR and the vehicle. The regulator responds to what it is told, and the quality of the ground. It in turn tells the alternator to put out according to what it thinks is happening at the battery. All of these things can be affected by bad/loose connections. Get 2 good voltmeters (check their internal batteries) and do some basic tests. Any electrical system can be fooled into reading high or low based on bad connections. I can talk you through it from there. Get in touch with me and I will explain further.
John
ncr2276@hotmail.com
p.s. A late model alternator with a built in regulator will sometimes simplify the repair and still read accurately on the ammeter if hooked up correctly .

 

[POPPAWS BRONCO]

John I sent you a reply, I did not know there was an external VR so it has not been tested this all makes me feel like my old Alt was not bad. I'll take some pics this afternoon when I get home again.


Hey!!! Let me hold a dollar I'm in the middle of a restore here!

 

[DirtDonk]

And you said you changed out a lot of existing wiring too. Just what did you modify?
Here again is where those pics might come in handy. It's possible you don't even have the regulator connected to the alternator if you moved a wire here or there thinking you didn't need it.

Paul

 

[POPPAWS BRONCO]

https://vimeo.com/190175475
New Alt was bad (that's my luck) tested new one and got a new regulator this time no wires were removed on the passenger side fender. Removed a lot from the other side

removed wires That box in pic is removed now. Ignition wire goes to Fast EFI now

engine off

engine on


Hey!!! Let me hold a dollar I'm in the middle of a restore here!

 

[5001craig]

I had a very similar problem. I kept blowing expensive headlights. Every time I troubleshot it after getting home, I was seeing ~14 volts. Then one night after driving home with a flashlight (fortunately, I always carry a good flashlight), I troubleshot it running and realized it was putting out similar voltage to you.

I ditched the OEM alternator/regulator and installed a one wire alternator. Trouble was gone instantly. Except the belt needs to be a good one and fairly tight when staying with the V-belt. I can't remember where I got my alternator but it was from one of the EB vendors. I think TBP but not sure.

 

[Steve83]

...no wires were removed on the passenger side fender. Removed a lot from the other side...

The alternator wiring is mostly on the passenger front between the alternator & VR (which is to the R side of the radiator).

 

[POPPAWS BRONCO]

Thanks for your help tonightJohn. This place is truly awesome and has the best people!


Hey!!! Let me hold a dollar I'm in the middle of a restore here!