1974 Dart regulation issue.

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NoahSewal

NoahSewal

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My charging system in my dart is really wacky. It will regulate up until about 2k rpm and then ones I rev it any higher it will shoot up and stop regulating. I've got a new alternator installed. I also tried replacing the regulator with no luck. Sometimes it will go away for a few days and then it will come back. Could it be an issue with the regulators ground or possibly a bad field connection on the alternator? Im just looks for someone's input if they have ever had this issue and how they resolved it. All inputs are appreciated!
 
NoahSewal said:
Could it be an issue with the regulators ground or possibly a bad field connection on the alternator
Click to expand...
Yes!:lol:


Sorry!

How are you determining it is no longer regulating?

Easy to provide a good ground to your VR.

did it do this with old alt? Old VR?

I would check every inch of wire on the field wires from the alternator to the VR, an intermitant short on the right field wire from the alt to the VR would provide full charging by the alt.

One field wire gets 12v, the other goes to the VR which regulates the ground to vary the field streingth to match charging to the load.

If that wire was grounded then the alt field will see a full 12v and go to max charging.
 
Last edited:
NoahSewal said:
and sand a better ground for the regulator when i get home
Click to expand...
You can just run a jumper from clean metal of VR to battery negitave. if the problem is happenjng and instany goes away when the jumper is added you have your solution. Then you can go about making the ground better.
 
The later models have a engine harness connector in the engine bay, made of white plastic. Alt' wires, temp sender, etc.., goes through them. They melt and cause intermittent short circuits.
 
When I saw the title, I thought "Great. More regulations. What now?"
 
PAY ATTENTION to what Redfish posted above^^


There are several issues at play when overcharging

"In no particular order"

There could be some "weird" thing going on with your alternator--loose bearings / shaft play, I know not what--that are somehow causing something to move and ground the VR connected field. But that would be a stretch

Not sure what might be RPM related--check the belt!!!

So far as "the rest of it" I've written dozens of times

VOLTAGE DROP!!! Make certain that the VR is actually AT battery ground, and make sure VR IGN terminal is "same as battery" --and they usually are not

1...Make absolutely certain VR is grounded. Remove, scrape around bolt holes, re-install with star lock washers. Not a bad idea to add a no10 jumper from the VR mounting bolt to the block

2...CHECK the VR connector for corrosion, and work it in/out several times to "scrub" the terminals and "fell" for tightness

3...In your case, remove and carefully inspect the brushes and slip rings for condition, impacted dirt/ grease etc in the brush holders, any oddity that might indicate a problem. Look up in the shop manual and do a field current test

4...To check for voltage drop, turn key to "run" with engine stopped. Stab one probe of your meter into the top of the battery + post. Connect the other as close as you can get to the VR IGN terminal, which is likely the ballast "key" side. This is the two terminals at one end of the ballast with a short jumper in between. You are hoping for a very low reading, the lower the better. Anything over about .3v you should try to see what is happening. One "workaround" is to add a relay to feed the ignition/ VR power. Cut the "ignition run" coming out of the bulkhead, use the bulkhead end to feed a Bosch relay. Connect the power contact through a big fuse/ breaker to the starter relay stud or other "solid" battery point. Connect the remaining contact to the engine bay end of the "run" wire you cut. Ground the other end of the relay coil

5...To check VR GROUNDing.......run engine at fast idle, and make this check with all accessories off, and again with everything on--blower, lights, etc. Stab one probe into the battery NEG terminal and the other into the VR mounting flange. You are hoping for a very low reading, and zero is perfect
 
On an unrelated note, have you bypassed the seat belt interlock so you don't have to worry about that?
 
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