Hello All
I hope someone can shed some light on this issue
I have just finished a complete restoration, new alternator, wiring harness, voltage regulator, battery, etc
Ran for a couple of weeks great, then the gen light comes on. Check the regulator, and here is the voltages when running:
term 1 (blue) 5.3 volts, term 2 (white) 5.7 volts - goes to 21 volts when engine is revved, term 3 (org) is 12.4 volts, term 4 (brown) is 5.2 volts So since I am only getting 5.2 volts out of terminal 4, and the battery (term 3) is at 12.4 volts, the gen light should be on since it is not charging - so lets change the regulator.

Read alot of posts here, and put a Wells VR715 electronic regulator on as recommend by everyone
Generator light is now off, but the battery voltage is still only 12.4 volts.
Here are the new readings:
term 1 is 11.4 volts, term 2 is 11.4 - goes to 27 volts when revving, term 3 is 12.4 volts, term 4 is 12.1 volts.
Why would I not be getting 14.5 volts? I drove the car last night with headlights on, etc, and the battery voltage never dropped, but I know something is not right. I am suspecting the new regulator (it was in a box, but it wasn't sealed), but maybe I am missing something else.
Thanks for your suggestions

Regulator chassis read the same ground as alternator and battery negative terminal?
Regulator chassis grounded good to radiator support?
Radiator support grounded good to engine block & alt?
Engine grounded good to battery negative terminal?

You can always take the reg & alt to Advance Auto and have them checked either together or individually for operation.

That high voltage on term 2 is all wrong, way wrong.

Make sure the regulator body is grounded. Make sure the radiator support is grounded.

On a 68, the reg should mount with 3 rubber well nuts. These insulate the regulator from the rad support, so a separate ground wire is used, make sure it's there and has a good connection.

When I put my car back together after paint, the whole darned rad support was not getting a good ground, too much new paint! Ended up moving the small ground pigtail from the battery cable from the inner fender to the rad support, and using lots of star washers under lots of bolts.

I know the regulator is grounded ok on the rad support (I have nutserts in 2 of the 3 regulator mounting holes) and the know I grounded the rad support to the subframe with a jumper. I will check that jumper, and put a jumper from the inner fender ground (off the battery) to the rad support also.

.

Rather than "knowing" how 'bout getting out a voltmeter?
(note that I knew mine was properly grounded too, but it was not.)

Put one meter lead on the regulator case, the other on the alternator case. Do you read zero volts?

Rather than "knowing" how 'bout getting out a voltmeter?
(note that I knew mine was properly grounded too, but it was not.)

Put one meter lead on the regulator case, the other on the alternator case. Do you read zero volts?

Jim....Can the spade wire connection on the back of the voltage regulator be used for a ground connection??

No, its on the voltage sense line and a condensor, another term for capacitor, reduces the noise generated by the mechanical contacts making and breaking.

Ground the case of the reg either by a strap from underneath a bolthead to the radiator support, or make a short jumper to do the same, or lengthen the jumper to the drvr side ground screw from the left headlamp.

No, its on the voltage sense line and a condensor, another term for capacitor, reduces the noise generated by the mechanical contacts making and breaking.

Ground the case of the reg either by a strap from underneath a bolthead to the radiator support, or make a short jumper to do the same, or lengthen the jumper to the drvr side ground screw from the left headlamp.


I don't have this so called condensor hooked up to the back of the regulator!....Would this explain why I hear a clicking noise coming from the voltage regulator when I switch on the ignition?.....The noise sounds like the points clicking inside the regulator.

Ron, if you're hearing it on your AM radio speaker, then yes, the capacitor will eliminate it. If you're just hearing the relays click, well that's what they do, tho I don't remember them being that loud.

The capacitor is no longer available, and is not reproduced (as of a couple of years ago). I used a conventional condensor for a points type distributor, and the connector from a "temp sender" repair kit to replace it.

The wells vr715 reg (at autozone for less than $15) is silent.

As for the ground wire, there is a small hole in the regulator case, the ground wire has a ring terminal and uses a sheet metal screw to attach it. The condensor attaches with this same screw. Another sheet metal screw attaches the other end of the ground wire to the rad support, outboard of the regulator.

Thanks for all the tips
Checked all the grounds - every one has a star washer under it. Ground pigtail from battery is bolted onto rad support. I have a ground jumper from the engine to the firewall, and from the engine to the subframe.
Used my ohmmeter and get 0 ohms from neg post of battery to regulator case and to alternator.
With engine running, get 0 volts from regulator case to alternator case, 12.4 volts from output on alternator to alternator case, and output on alternator to regulator case.
There is a stud on the back of the alternator marked GND, but this is for a condensor as discussed.
Ran a ground wire directly from alternator case to regulator case - no change.

I pulled the alternator & regulator off and will get them checked tommorow at Auto parts store.

Any other ideas?

Check the two-wire connector on back of the alt. Are both wires locked into place?
Is blue wire to #2 or the right terminal?
Is white wire to #1 or left terminal?

By your readings, 5.7 volts, its telling the alt to max output by giving alot of field voltage, or current actually, to make a heavy field, and the alt is producing as shown by the unregulated 27 volts. Reg is bad, I bet.

Ron, if you're hearing it on your AM radio speaker, then yes, the capacitor will eliminate it. If you're just hearing the relays click, well that's what they do, tho I don't remember them being that loud.

The capacitor is no longer available, and is not reproduced (as of a couple of years ago). I used a conventional condensor for a points type distributor, and the connector from a "temp sender" repair kit to replace it.

The wells vr715 reg (at autozone for less than $15) is silent.

As for the ground wire, there is a small hole in the regulator case, the ground wire has a ring terminal and uses a sheet metal screw to attach it. The condensor attaches with this same screw. Another sheet metal screw attaches the other end of the ground wire to the rad support, outboard of the regulator.


OK.....Thanks for the regulator ground info.:thumbsup:

Test machine at autozone shows alternator is bad (just prints out a bad label, doesn't say what) and my original regulator tested bad too. Too much of a coincidence since they were both new parts 4 weeks ago (along with everything else). We will see when I put a new alternator on what happens!

did your new wells reg test ok?

my new wells reg tested ok except for one test, but a new one in the box straight off the shelf tested the same way. The store manager said the test machine has not tested the electronic regs correct before, and he had to have his tester repaired (the tester is supplied by wells also).

Wonder what the name of the test is? Strange a direct replacement, elec for mech, would not pass.

Would have to get a schematic for the elec regulator and compare to mech regulator.

The test was done on the Wells machine at Auto Zone

- the alternator was the culprit

Thanks for all your help