Voltage Regulator?

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TF360

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Installing a new Voltage Regulator and it's painted on both sides, plus I just painted the inner fender over the holes. 1974 Plymouth Duster- Do I need to sand any paint off around the holes. Is it grounded there? The two bolts that hold it on are serrated, so they will dig in a little. What do you guys think?
 
Yes it grounds thru the mounting bolts. Scrape off the holes on the bottom of V R, and holes where you mount it. I always put a star washer on the bolts between the V R, and mounting holes. You want clean metal,on all mounting surfaces, no paint crud etc. Make sure bolts are a good tight fit.
Dave
 
If you don't want to scrape paint you could create a dedicated ground wire jumper
 
MUST be grounded and I urge you, when you get it running, to run tests to make certain it is not only grounded, but does not suffer voltage drop in either the ground or hot circuit. This causes over charging because the VR "thinks" the battery is low from the drop
 
I would use a dedicated ground jumper wire. The sheet-metal screw was good enough to last the factory warranty, but caused untold problems later when rusty. It will overcharge if you don't get a good ground.
 
I have one of the $10 voltage regulators, came on the car, with just the 2 terminals, Ignition & Field. It appears fairly new.
Battery is fresh, reads 12.7V standing.
When I got the car the regulator was not really bolted tight to the firewall and the ammeter had really wild positive swings. After tightening the bolts the swings are lessened.
I have run a dedicated ground to the regulator mounting bolt.
My alternator puts out 15.0 to 15.2 volts.
The battery voltage reads 14.7 to 15.0 when running.
The ammeter gauge jumps high scale when started to small jumps after a few minutes, and sits steady while running down the road. It does have a minimal jump with the turn signals blinking.
I'm getting a bit of battery fluid venting.
Is this the correct output from the regulator?
If not could it have been from poor mounting/grounding?
 
MUST be grounded and I urge you, when you get it running, to run tests to make certain it is not only grounded, but does not suffer voltage drop in either the ground or hot circuit. This causes over charging because the VR "thinks" the battery is low from the drop
Yes it does. Don't ask me how I know. :BangHead::BangHead::BangHead:
 
I have one of the $10 voltage regulators, came on the car, with just the 2 terminals, Ignition & Field. It appears fairly new.
Battery is fresh, reads 12.7V standing.
When I got the car the regulator was not really bolted tight to the firewall and the ammeter had really wild positive swings. After tightening the bolts the swings are lessened.
I have run a dedicated ground to the regulator mounting bolt.
My alternator puts out 15.0 to 15.2 volts.
The battery voltage reads 14.7 to 15.0 when running.
The ammeter gauge jumps high scale when started to small jumps after a few minutes, and sits steady while running down the road. It does have a minimal jump with the turn signals blinking.
I'm getting a bit of battery fluid venting.
Is this the correct output from the regulator?
If not could it have been from poor mounting/grounding?

The battery voltage is not too bad. The alternator output is not too bad. There will ALWAYS be a voltage drop between alternator output and battery in these girls, unless you bypass the entire circuit with a large ga. wire direct from alternator to battery IE no 6 wire, etc

Here is the deal. There is typically voltage drop in the VR / ignition circuit which causes the battery to run high. There are two ways to check for this

1.....With engine warm, battery "normalized" and engine running on fast idle (to simulate low/ med cruise RPM and to insure that VR/ alternator are "up") Measure ignition voltage where it goes to ballast resistor. Measure from ballast IGN "run" terminal to VR ground. If this is in spec (see chart in service manual) 13.8--14.2 when warm, then VR is OK and any other voltage "at battery" means a harness voltage drop problem

2....Second way (how I do this) is turn key to "run" engine stopped. Measure between same point as above (ballast IGN RUN) and battery PLUS terminal. You are hoping for a very low reading. If your read more than a few tenths of a volt you need to get into "why." ----and fix it

Just one way is to use a relay triggered by the key, to power underhood loads

Let's say you measure .5V in test "2." This means that if the VR is actually charging at 14.2, and you have .5V reading with test "2" then that .5V will ADD to the 14.2, and the battery will run about 14.7V

This drop comes from the VR supply path which is ..........battery---------starter relay stud----------fuse link--------through the bulkhead on RED ammeter wire--------through ammeter-------out on BLACK ammeter wire----------to underdash welded splice-----------branch off to ignition switch connector---------through connector, switch, .........back out switch connector..........on "ignition run" (IGN1) .........back out through bulkhead connector.............to underhood ignition loads.

EACH OF THE POINTS above, between the dots is a point of bad connection and potential voltage drop. These drops ADD. IE if you have .2V drop through switch, and another .4V through bulkead connector RED terminal, and .1V through bulkhead terminal for the ignition "run" wire, these all add up in series
 
The battery voltage is not too bad. The alternator output is not too bad. There will ALWAYS be a voltage drop between alternator output and battery in these girls, unless you bypass the entire circuit with a large ga. wire direct from alternator to battery IE no 6 wire, etc

Here is the deal. There is typically voltage drop in the VR / ignition circuit which causes the battery to run high. There are two ways to check for this

1.....With engine warm, battery "normalized" and engine running on fast idle (to simulate low/ med cruise RPM and to insure that VR/ alternator are "up") Measure ignition voltage where it goes to ballast resistor. Measure from ballast IGN "run" terminal to VR ground. If this is in spec (see chart in service manual) 13.8--14.2 when warm, then VR is OK and any other voltage "at battery" means a harness voltage drop problem

2....Second way (how I do this) is turn key to "run" engine stopped. Measure between same point as above (ballast IGN RUN) and battery PLUS terminal. You are hoping for a very low reading. If your read more than a few tenths of a volt you need to get into "why." ----and fix it

Just one way is to use a relay triggered by the key, to power underhood loads

Let's say you measure .5V in test "2." This means that if the VR is actually charging at 14.2, and you have .5V reading with test "2" then that .5V will ADD to the 14.2, and the battery will run about 14.7V

This drop comes from the VR supply path which is ..........battery---------starter relay stud----------fuse link--------through the bulkhead on RED ammeter wire--------through ammeter-------out on BLACK ammeter wire----------to underdash welded splice-----------branch off to ignition switch connector---------through connector, switch, .........back out switch connector..........on "ignition run" (IGN1) .........back out through bulkhead connector.............to underhood ignition loads.

EACH OF THE POINTS above, between the dots is a point of bad connection and potential voltage drop. These drops ADD. IE if you have .2V drop through switch, and another .4V through bulkead connector RED terminal, and .1V through bulkhead terminal for the ignition "run" wire, these all add up in series
@67Dart273 I found your test criteria on another post and I was out checking!
With the key on I get 1.1V at the ign terminal on the regulator. Unplugged I get .5V on that wire.
I get .9V at the blue wire on the ballast, plugged in but not running. Unplugged I get .45V

Interestingly, I get 12.4V basically battery voltage at the ign terminal of the regulator with the wire disconnected, motor not running. Is this normal or is it shorted through?

The underdash wire from the ammeter has been replaced with 10ga and the splice resoldered and 10 ga run back out.
It was spliced with lampcord and wirenuts when I got the car, don't ask..... :eek:
The 2 heavy leads through the bulkhead connector were burned off, and the new wiring is run through a grommet in the firewall.
I have cleaned the remaining bulkhead connector leads.
This is a convertible that sat with a destroyed top, the floors have been replaced, and there is actually some small spots of surface rust above the inst panel under the curved part of the dash.
I'm thinking there is most likely some internal wire corrosion..... :(
 
The 1.1 is likely the important reading. You must measure with everything connected normal, because current through the circuits is what causes the drop in the first place. You measured this 1.1V exactly where? At the VR IGN terminal to battery PLUS?

"Let's say" your VR is correctly operating at 14V nominal. That 1.1 gets added to, so the battery will "run" at 15.1

One way I've suggested curing this is to cut (electrically, several ways physically to do so) the dark blue "IGN1" "run" wire coming out of the bulkhead into the engine bay. Feed the bulkhead connector end to a relay coil, feed the relay contact from the starter relay with a large fuse or breaker, say, 20A, and connect the engine bay end of the cut wire to the relay switched // load contact

Now the VR and underhood loads will be fed directly from the starter relay, instead of "loading" through the "circuitous circuit" through the harness
 
The other issue which I forgot to mention is the ground side. Just like the "hot" side, the ground side of the VR MUST be right at 'same as' battery NEG potential (voltage) You can add grounding wiring between the VR and battery, what I like to do is add a no4 starter cable (eyelet to eyelet) from the engine block to a good firewall ground, such as the master cylinder mounting stud

On the V8s there are unused holes at the rear of the driver side head

This really sums it all up. For the VR to properly regulate at the correct voltage, both the ground, and the power connection MUST be at "same as battery" voltage. Current through a circuit, and too small wire, bad connections, or switches with deteriorated contacts all add up to drop voltage when current flows
 
The battery voltage is not too bad. The alternator output is not too bad. There will ALWAYS be a voltage drop between alternator output and battery in these girls, unless you bypass the entire circuit with a large ga. wire direct from alternator to battery IE no 6 wire, etc

Here is the deal. There is typically voltage drop in the VR / ignition circuit which causes the battery to run high. There are two ways to check for this

1.....With engine warm, battery "normalized" and engine running on fast idle (to simulate low/ med cruise RPM and to insure that VR/ alternator are "up") Measure ignition voltage where it goes to ballast resistor. Measure from ballast IGN "run" terminal to VR ground. If this is in spec (see chart in service manual) 13.8--14.2 when warm, then VR is OK and any other voltage "at battery" means a harness voltage drop problem

2....Second way (how I do this) is turn key to "run" engine stopped. Measure between same point as above (ballast IGN RUN) and battery PLUS terminal. You are hoping for a very low reading. If your read more than a few tenths of a volt you need to get into "why." ----and fix it

Just one way is to use a relay triggered by the key, to power underhood loads

Let's say you measure .5V in test "2." This means that if the VR is actually charging at 14.2, and you have .5V reading with test "2" then that .5V will ADD to the 14.2, and the battery will run about 14.7V

This drop comes from the VR supply path which is ..........battery---------starter relay stud----------fuse link--------through the bulkhead on RED ammeter wire--------through ammeter-------out on BLACK ammeter wire----------to underdash welded splice-----------branch off to ignition switch connector---------through connector, switch, .........back out switch connector..........on "ignition run" (IGN1) .........back out through bulkhead connector.............to underhood ignition loads.

EACH OF THE POINTS above, between the dots is a point of bad connection and potential voltage drop. These drops ADD. IE if you have .2V drop through switch, and another .4V through bulkead connector RED terminal, and .1V through bulkhead terminal for the ignition "run" wire, these all add up in series
OK,all this makes perfect sense as to why I get a higher read at the battery.
Using your method #1 I get a fairly steady reading of 13.9V, so I'll use the 'A' word and assume the regulator is good.
Oh yeah, ever hear the saying "The right hand doesn't know what the left hand is doing"?
Well that applies to this statement:
Interestingly, I get 12.4V basically battery voltage at the ign terminal of the regulator with the wire disconnected, motor not running. Is this normal or is it shorted through?
My right hand held the probe on the ign tab, while my left hand held the probe on the positive battery terminal! :rolleyes:
If I run across an under dash harness at a reasonable $$ I may spring for it. If things deteriorate further and I have more gremlins, I'll just build a replacement.
67Dart273 thanks for you help, much appreciated.
 
The 1.1 is likely the important reading. You must measure with everything connected normal, because current through the circuits is what causes the drop in the first place. You measured this 1.1V exactly where? At the VR IGN terminal to battery PLUS?

"Let's say" your VR is correctly operating at 14V nominal. That 1.1 gets added to, so the battery will "run" at 15.1

One way I've suggested curing this is to cut (electrically, several ways physically to do so) the dark blue "IGN1" "run" wire coming out of the bulkhead into the engine bay. Feed the bulkhead connector end to a relay coil, feed the relay contact from the starter relay with a large fuse or breaker, say, 20A, and connect the engine bay end of the cut wire to the relay switched // load contact

Now the VR and underhood loads will be fed directly from the starter relay, instead of "loading" through the "circuitous circuit" through the harness

The other issue which I forgot to mention is the ground side. Just like the "hot" side, the ground side of the VR MUST be right at 'same as' battery NEG potential (voltage) You can add grounding wiring between the VR and battery, what I like to do is add a no4 starter cable (eyelet to eyelet) from the engine block to a good firewall ground, such as the master cylinder mounting stud

On the V8s there are unused holes at the rear of the driver side head

This really sums it all up. For the VR to properly regulate at the correct voltage, both the ground, and the power connection MUST be at "same as battery" voltage. Current through a circuit, and too small wire, bad connections, or switches with deteriorated contacts all add up to drop voltage when current flows

I was out testing again, I should have refreshed the page to see your posts.

The regulator reads fairly steady at 13.9V as in your test#1 with the engine running, I assume it's OK.
So in post 10 you basically use the blue ign wire currently feeding both the regulator and the ballast resistor to trigger a relay that then delivers 12V to the regulator and the ballast?

I have a dedicated 10ga ground from battery neg to the regulator mount. I also run a battery cable ground from a bell housing bolt to the firewall. Belt & suspenders approach!
 
The regulator reads fairly steady at 13.9V as in your test#1 with the engine running, I assume it's OK.
So in post 10 you basically use the blue ign wire currently feeding both the regulator and the ballast resistor to trigger a relay that then delivers 12V to the regulator and the ballast?

Exactly that.

On newer cars it gets worse. Some had more loads on that circuit, and later cars had an inline engine harness disconnect connector (it is white if you ever see one) and they were REAL trouble, in part because they ran the alternator output through the thing.
 
Exactly that.

On newer cars it gets worse. Some had more loads on that circuit, and later cars had an inline engine harness disconnect connector (it is white if you ever see one) and they were REAL trouble, in part because they ran the alternator output through the thing.
Thanks again. I'll get a relay installed tomorrow and report the results.
 
Relay installed and appears to be doing the trick. Battery voltage is steady at 13.9-14.1 after running down the road and recharging from the starter draw. Even immediately after start it was reading 14.7-14.9, not the 15.2 I was getting earlier!
If I understand this correctly, eliminating the voltage drop in the factory wiring and letting the voltage regulator read the actual battery level.
FYI, when I cut into the blue ignition wire there was evidence of corrosion, some slight tarnishing of the copper strands!
Again, thanks for sharing your knowledge.
 
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