12 volts?

Mo Mars · #1 (**permalink**) 06-05-2016, 12:48 PM

Having an issue with charging. My gauge showed me charging at 13-14 volts, the alternator stater went bad and I had that repaired, bought a new circuit regulator, replaced the battery and ground cable and now the gauge is only reading just over 12 volts.......where am I missing what I had before?

Tommy · #2 (**permalink**) 06-05-2016, 01:10 PM

It sounds like the gauge is reading battery voltage only (no charging). Either something else is broken/not fixed, or something is not connected correctly. Without knowing more about your particular car/engine/alternator/charging system, I can't offer much more.

DWRAT · #3 (**permalink**) 06-05-2016, 01:13 PM

What does your gauge read when your RPM's are above 2,000?

olddog · #4 (**permalink**) 06-05-2016, 01:19 PM

Just because you put new parts in, it does not mean all parts are working. You could have gotten a bad part. You could have installed something incorrectly. You could have shorted and damaged a part during the install. I'm not trying to be mister negative here. We all make mistakes, and when things do not look right, odds are something is wrong.

I recommend verifying your voltage with a good multi meter, if you have access to one. See what the battery voltage is with key off. Then see what it is with the engine running.

I'm thinking a battery should be a bit under 13 volts with the key off. With the engine running above idle, I would expect 13.5 volts give or take. I would check at the battery. If that is quite different than your gauge, then I would test again at the gauge to confirm if it is the gauge or the connections.

Mo Mars · #5 (**permalink**) 06-05-2016, 01:52 PM

John York built 351, new Pertronix igniter 2 with matching coil. I removed the Ford height set up per John and then I started having this problem.

Large Arbor · #6 (**permalink**) 06-05-2016, 05:08 PM

I would start with checking to be sure the alternator is working. With the key on take a voltage reading at the alternator, you should have 12 V. Once that is confirmed I would look at the connections at the voltage regulator, making sure you have continuity on all wires. Only a few things it can be. I had a similar issue and their was a fuseable link in my cable from the alternator to battery. That link was broken and hence no charging.

Phil

DanEC · #7 (**permalink**) 06-05-2016, 05:48 PM

If it's only showing 12 V it sounds like the alternator isn't receiving a signal to meet demand - meaning the voltage regulator may not be regulating. My experience with a bad VR was that the alternator defaulted to putting out a straight 12 V no matter what load was put on it. Fords based systems are kind of weird, the VR has to be excited to go into action.

Mo Mars · #8 (**permalink**) 06-06-2016, 06:40 PM

Ok I have replaced the voltage regulator twice, jumped the alternator over to check if it would push 16 volts on the gauge.....it did so that told me it was charging, I then replaced the field wire from the alt. to the vr.....nothing so I then I replaced the alt wire from the vr. to the solenoid...still nothing

Large Arbor · #9 (**permalink**) 06-06-2016, 07:32 PM

Mo Mars,

Based upon what you said, I think I would try a different battery. I recently had a brand new one fail right out of the box.

Phil

Tommy · #10 (**permalink**) 06-07-2016, 04:33 AM

As I said before, we need more detail in order to provide more than "here's what happened to me" advice. There are several types of alternators. Perhaps this link will help.

1795 · #11 (**permalink**) 06-07-2016, 05:22 AM

Quote:

Originally Posted by DanEC

If it's only showing 12 V it sounds like the alternator isn't receiving a signal to meet demand - meaning the voltage regulator may not be regulating. My experience with a bad VR was that the alternator defaulted to putting out a straight 12 V no matter what load was put on it. Fords based systems are kind of weird, the VR has to be excited to go into action.

I am not sure how your system is wired, but tie a look at how it was previously wired before the changes. My MGB race car was not charging the battery and like Dan said, I had to wire in an idiot light so that the alternator would then get excited and send charge to the battery. Went from having 12.5 volts to the battery to 14 volts.

I am not sure what the Ford height setup is, but when you removed that things started going bad, may need to reconsider putting that back in and seeing what happens?

Large Arbor · #12 (**permalink**) 06-27-2016, 02:37 PM

I had a fusible link in the alternator to battery feed which resulted in no charging. I would agree with checking continuity on wiring from VR to ALT and then battery to make sure you are not getting a drop somewhere in the circuitry.

Phil