capnswanny
Active Member
It all worked out fine for my son, he drove the GMC instead! 
Overcharging 68Dart...need some short fused help (pun intended:)
- Thread starter capnswanny
- Start date
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Inductive clamps are fairly common these days.
That's one option. A short discussion in this thread.
67 Barracuda alternator with 2 FLD connections
Here's another one
[FOR SALE] - MAC TOOLS EM110 inductive pick up amp clamp
There are some other versions too. Used to be pretty common underdash gage (For those Chevies that came with nothing but a gas gage and a speedometer). I know I have a couple of those as well.
Doubt it.
The over voltage is only a VR cir issue
Have you measured the voltage to the field wire when the charging voltage is 12 to 13 and again when it is 15 to 17?
Best guess is at 15 to 17 the voltage will be close to 11 to 12v. And when charging at 12 to 14 it will be in the 6 to 9v range
capnswanny
Active Member
Thanks for the links!
I do love Fluke's meters (it's all we use in the Navy) but the $280 price tag on their DC clamp is a hard pill to swallow!!
I do love Fluke's meters (it's all we use in the Navy) but the $280 price tag on their DC clamp is a hard pill to swallow!!
capnswanny
Active Member
I haven't, but that would be prudent. I'll be sure to measure that when I get back to the grind with an ammeter inline with the load to the cabin!
And, well crap! I noticed that my voltage gauge and ammeter would both increase under throttle, to the extreme once the car was warmer...even before the cooling fan turned on. I had hoped that they were relative, but it sounds like you're saying that they are up to maybe a cutoff point as set by the VR?
Thank You!
The VR should maintain a constant voltage to the system assuming the alternator can supply sufficient current.
Essentially the VR will increase or decrease the voltage/current to the field to maintain the correct output voltage from the alternator.
Think of it this way.
Your battery is a bucket.
It has a small hole in the bottom, (that is the load of the car, headlights, ignition, etc)
Your alternator is a pitcher,
when the engine is off no water is being poured from the pitcher into the bucket. So the water level in the bucket starts to drop.
With the engine started, you are pouring water from the pitcher into the bucket. At idle you are pouring a very small amount of water into the bucket, not enough to equal the amount going out of the hole in the bottom of the bucket.
Now you are at a higher rpm and you are pouring more water from the pitcher into the bucket faster than the water is leaking out the hole in the bottom, and the bucket is slowly filling up. to keep it from overflowing you start pouring a little less water into the bucket. Untill you are able to pour just enough water into the bucket to maintain the level in the bucket.
You are the VR!
By tipping the pitcher more or less you are changing the volume of water going into the bucket.
The fact that the pitcher is constantly pouring way more water into the bucket than is running out the bottom is the issue, nothing that the engine or the rest of the car is doing can cause that
EXCEPT...
If the voltage to the VR is low it will try to tip the pitcher more than it should and over charge.
To check that, check the voltage going into the VR when it is charging at 15 to 17 volts
I know that I am interchanging current and voltage when talking about the VR, but if the input voltage to the VR is low it will think that the alternator needs to increase in voltage so it will cause the field coil to be fully energized more of the time causing a higher output voltage.
I hope my wandering example is not too confusing
Essentially the VR will increase or decrease the voltage/current to the field to maintain the correct output voltage from the alternator.
Think of it this way.
Your battery is a bucket.
It has a small hole in the bottom, (that is the load of the car, headlights, ignition, etc)
Your alternator is a pitcher,
when the engine is off no water is being poured from the pitcher into the bucket. So the water level in the bucket starts to drop.
With the engine started, you are pouring water from the pitcher into the bucket. At idle you are pouring a very small amount of water into the bucket, not enough to equal the amount going out of the hole in the bottom of the bucket.
Now you are at a higher rpm and you are pouring more water from the pitcher into the bucket faster than the water is leaking out the hole in the bottom, and the bucket is slowly filling up. to keep it from overflowing you start pouring a little less water into the bucket. Untill you are able to pour just enough water into the bucket to maintain the level in the bucket.
You are the VR!
By tipping the pitcher more or less you are changing the volume of water going into the bucket.
The fact that the pitcher is constantly pouring way more water into the bucket than is running out the bottom is the issue, nothing that the engine or the rest of the car is doing can cause that
EXCEPT...
If the voltage to the VR is low it will try to tip the pitcher more than it should and over charge.
To check that, check the voltage going into the VR when it is charging at 15 to 17 volts
I know that I am interchanging current and voltage when talking about the VR, but if the input voltage to the VR is low it will think that the alternator needs to increase in voltage so it will cause the field coil to be fully energized more of the time causing a higher output voltage.
I hope my wandering example is not too confusing
capnswanny
Active Member
Quick question for you guys (and gals) if you have a minute... I haven't gotten back to trouble-shooting this problem, the car is in time out right now while I sort out my thoughts.
I replaced the original (dead) VR with a like VR from NAPA. That's when I started paying attention to the over-voltage condition I have.
After reading posts on the forum, I replaced that VR with a heavier duty Standard VR-106. But, due to the constraints of the mounting location, I moved it from its vertically mounted location on the firewall, to the inner fender mounted horizontally.
So here's the question, would mounting the VR-106 on the horizontal, vice vertical, cause lack of heat dissipation from the resistors mounted on the bottom, and consequently failure of the VR to operate properly?
I'm gonna get back to this in full-force this weekend and work through all the suggestions you've given me.
Thanks to you all for your help thus far!!
-Corey
I replaced the original (dead) VR with a like VR from NAPA. That's when I started paying attention to the over-voltage condition I have.
After reading posts on the forum, I replaced that VR with a heavier duty Standard VR-106. But, due to the constraints of the mounting location, I moved it from its vertically mounted location on the firewall, to the inner fender mounted horizontally.
So here's the question, would mounting the VR-106 on the horizontal, vice vertical, cause lack of heat dissipation from the resistors mounted on the bottom, and consequently failure of the VR to operate properly?
I'm gonna get back to this in full-force this weekend and work through all the suggestions you've given me.
Thanks to you all for your help thus far!!
-Corey
67 darts are mounted to the firewall next to the master cyl. Screw terminal to the top.
I don't think that's the issue.
I don't think that's the issue.
What was wrong with it?
That can be a very good clue about a problem in the system.
Need to see what makes the VR-106 a 'heavier duty' regulator to know if there is any functional difference.
capnswanny
Active Member
Great idea! I pulled the top on the original Echlin VR-32 and found no electrical damage, but it looks like it’s had some moisture accumulation and much corrosion on the connections. I would suspect the corrosion alone could’ve caused some problems.
capnswanny
Active Member
Also pulled the top on the NAPA replacement and all looks good electrically.
They sure wound the coil better on the Echlin VR....
It's possible the oxidation where the resistors are rivetted continues into the connection. Other than that, if the points are good, its good.
The heavy duty VR has the screw adjustment. I think I've seen that in the service manual on the Essex built regulators. As far as I know they work the same way.
Since the fusible links aren't melted, and the point are fresh, there's no reason why it shouldn't work.
If there is a problem with votlage climbing beyond 14.9 its most likely that the regulator is 'seeing' the wrong voltage, or the somehow the regulator is being bypassed.
The heavy duty VR has the screw adjustment. I think I've seen that in the service manual on the Essex built regulators. As far as I know they work the same way.
Since the fusible links aren't melted, and the point are fresh, there's no reason why it shouldn't work.
If there is a problem with votlage climbing beyond 14.9 its most likely that the regulator is 'seeing' the wrong voltage, or the somehow the regulator is being bypassed.
Shop manual has the details of the regulators. I snipped some of the pictures to use in this post
Blowing voltage regulators
The drawings in the post that follows came from this booklet.
Alternators and Regulators 66-11 (Session 228) Master Technician's Service Conference
Blowing voltage regulators
The drawings in the post that follows came from this booklet.
Alternators and Regulators 66-11 (Session 228) Master Technician's Service Conference
capnswanny
Active Member
Thanks, I replaced this one because it just stopped charging period.
You guys have given me plenty of good ideas, I’m going to check the drop from batt to VR at when I get back to it...and monitor it at operating temperature. Also monitor/isolate current draw (something blew my 30A fuse).
Here’s a pic of the VR106 next to the NAPA replacement. Ohm readings are a little different than the “original”, and one end of the coil is tied to the sense terminal through a 10 Ohm resistor? The coil wire is heavier gauge, and a little better wrapped.
I’ll switch back to the original style when I fire it up again for testing.
There was definitely an excessive drop through the ignition/bulkhead wiring before I bypassed with a relay so....
Thanks again for all your help guys, it is much appreciated!!
-Corey
capnswanny
Active Member
Thanks!!
I find it amazing that the modern replacement VR are mechanical like the 54 year old OEM units.
One would think that electronic VR guts could fit nicely into the same housing.
One would think that electronic VR guts could fit nicely into the same housing.
A quick check for VR causing lack of to the rotor is to place a jumper from the "ign" side (power) to the controlled side "field".
If you haven't looked at this, posts 1, 2 and 5 show how it works.
Identifying Chrysler Alternators (1960-1976)
That might be for the optional alternators that were wired a little differently. I've seen some Chrysler info on them but can't recall where off the top of my head.
Only if you know the battery is close to the same voltage as the alternator is producing.
Otherwise measure the difference between the alternator output voltage to the voltage the regulator is seeing.
capnswanny
Active Member
capnswanny
Active Member
Understood, and Thanks!!
capnswanny
Active Member
I just want to say, you guys are a blessing to the community. I’ve read back through hundreds of posts here, and you are always on the spot to share your knowledge. Heck, you’ve even offered to drive to a persons house to help them out!!
The world needs more people like you.
Thanks!!
The world needs more people like you.
Thanks!!
capnswanny
Active Member
I’ve read this a number of times and I think it’s a very good analogy, Thanks!!
capnswanny
Active Member
I finally got back to it today.
I reinstalled the NAPA VR-32 style regulator grounded very well, and sense line (batt) through a relay.
I found what blew the 30A fuse, the aftermarket stereo I installed shorted out internally due to the high input voltage it was subjected to and blew its 10 A fuse. When I installed a new fuse, in ACC position it was pulling 20A (with it out, less than 1A.)
Question for you, is 5A normal draw by the coil in the ON key position (not running)?
It’s less than 1A with the distributor disconnected from the coil.
I cut the battery terminal off in case there was corrosion buried in there and I’m replacing it and the line to the starter relay. After that I’ll take some readings with the car running.
Thank You again for all your help!
-Corey
I reinstalled the NAPA VR-32 style regulator grounded very well, and sense line (batt) through a relay.
I found what blew the 30A fuse, the aftermarket stereo I installed shorted out internally due to the high input voltage it was subjected to and blew its 10 A fuse. When I installed a new fuse, in ACC position it was pulling 20A (with it out, less than 1A.)
Question for you, is 5A normal draw by the coil in the ON key position (not running)?
It’s less than 1A with the distributor disconnected from the coil.
I cut the battery terminal off in case there was corrosion buried in there and I’m replacing it and the line to the starter relay. After that I’ll take some readings with the car running.
Thank You again for all your help!
-Corey
Can't say for sure about the 5A,
Found this on a web site:
"How many amps does a ignition coil draw?
Ignition Coil (single oil-filled coil older vehicle) - 3 to 4 amps."
So 5 does not seem out of line.
but with the coil disconnected from the dist. there shoud be no draw from the coil.
How and where are you taking the amp reading?
capnswanny
Active Member
That sounds good...
I took the reading inline between batt and feed direct from ammeter. The less than 1A statement is because I’m using a gauge from Tractor Supply that does not have a very accurate scale. Basically the needle bumps up a hair with the distributor disconnected....but instrument panel was still inline.
This is the backyard ammeter I put together with a 30A breaker/switch that would allow me to connect/disconnect power at the gauge. :/
Thanks for the reply!!
-Corey
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