an electrical nightmare , please help , 1972 dart

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No. Be sure you scrape the paint away around the mounting screws, and if you can come up with any, "start" lock washers, either internal or external, are helpful


Thank you . I already installed the ground strap before getting your message , but did not scrape the paint away . There was some rust where it mounts on one side . I sanded it a little bit . I will do it over soon and try to get to some more bare metal there . I think it is grounded though . as per your previous posts , i did the voltage test from the NEG battery post to VR flange and got ZERO . I then got 0.02 with the headlight switch , heater , and air conditioner all on .

Right now the system is overcharging . Oddly , it is also overcharging with the voltage regulator unplugged from it's connector . I don't understand that . At a slow idle the meter was reading 13-14+ . With the RPM"S up it was going over 17 !
 
Then there is something causing field power fed to the alternator. FIRST thing to do VERY first thing is to disconnect both field terminal connections, and ohm the terminals to ground. Both should be OPEN (infinity) to ground, and just ?? a couple IE very low between the two. Check your connections and wiring to the field and VR

I have forgotten, you must be? using the 70/ later VR with the triangular connector? If so, the field terminal connected to the green wire is likely grounded.
 
Then there is something causing field power fed to the alternator. FIRST thing to do VERY first thing is to disconnect both field terminal connections, and ohm the terminals to ground. Both should be OPEN (infinity) to ground, and just ?? a couple IE very low between the two. Check your connections and wiring to the field and VR

I have forgotten, you must be? using the 70/ later VR with the triangular connector? If so, the field terminal connected to the green wire is likely grounded.


Yes , i am using the 70/ later VR with the two prong triangle connector . I think i am doing this right . With both field terminals disconnected . With the meter set to the 200 range in ohms , it read 54.3 with one probe on the lower field terminal blade ( where the blue wire goes ) and the other probe on a fender bolt ground . Then again on alternator housing , same readings . It does fluctuate slowly , going both up and down . Mostly it slowly drops one tenth at a time . It did this with the VR connected and without it connected . The top field blade ( where the green wire goes ) , that read : 1 to the far left of the display . is that infinity ? . it read the same for between the two field blades . 1 on the far left of the display .

I also checked for Ohm's from the green wire , between the VR connector , and the terminal connector . that read 00.3 on the 200 scale of the meter . However , it might be lower because when i touch the two leads of the meter together , that alone reads 00.2
 
I don't understand. This IS a standard "70's" Mopar alternator? And not something like a powermaster? Can you shoot a photo of it showing the back and terminals?

The field is a simple electromagnet, connected to the two field terminals. The light blue wire supplies 12V from the switched "ignition run." With that connected, and key "in run" you should read "battery" at the green field wire when disconnected at the regulator. The VR controls "the amount of grounding" on that green wire and that controls alternator output. IF the alternator is charging with the VR connected, either

the green field wire is grounded
the field is grounded on the "end" opposite the blue 12 supply wire
or this is an aftermarket alternator with a built in regulator, and IT is acting up

EDIT:

With both field terminals disconnected . With the meter set to the 200 range in ohms , it read 54.3 with one probe on the lower field terminal blade ( where the blue wire goes ) and the other probe on a fender bolt ground .

This right here says there is continuity from field to ground. The field may actually be shorted to the rotor itself, and grounding through the bearings. Try removing both brushes, and probe directly on the slip rings. In other words, with brushes removed, and with one probe on either slip ring, other probe on alternator case, should be open/ infinity

Inspect the brushes/ brush holders carefully for shorts.
 
I don't understand. This IS a standard "70's" Mopar alternator? And not something like a powermaster? Can you shoot a photo of it showing the back and terminals?

The field is a simple electromagnet, connected to the two field terminals. The light blue wire supplies 12V from the switched "ignition run." With that connected, and key "in run" you should read "battery" at the green field wire when disconnected at the regulator. The VR controls "the amount of grounding" on that green wire and that controls alternator output. IF the alternator is charging with the VR connected, either

the green field wire is grounded
the field is grounded on the "end" opposite the blue 12 supply wire
or this is an aftermarket alternator with a built in regulator, and IT is acting up

I don't understand either , this is all new to me . I am really lost . Thank you for your help .
The alternator is a remanufactured REMY unit , I recently got from rockauto . It's supposed to be a direct replacement . Pictures below .

This thing is charging with the VR disconnected too . though occasionally it does not charge at all . VR connected or not .

With the terminals connected , and the VR disconnected . With the key " in run " . the green wire is reading only 0.04 on the meter set to 20 . The blue field blade is getting around 10.00 .

this Alt. is probably crap , but maybe something else killed it ? I just got three used alternators at Carlisle . Two standard 60 amp two field , and one powermaster single wire , 90 amp with built-in regulator . maybe i should try one of those ?

Would any of this be caused by / or causing the grounding issue with the lights ? or would that be something different ?


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With the terminals connected , and the VR disconnected . With the key " in run " . the green wire is reading only 0.04 on the meter set to 20 . The blue field blade is getting around 10.00 .

You have "the typical problem" of a rebuilt. SOMEBODY left part of the insulator washer hardware out of the green brush holder. You are lucky you did not accidently connect the blue to that you'd have burned up the harness.

Next step is to take the alternator off, remove the brush holders and inspect them. Post photos if you cannot figure it out.
 
You should have a ground wire or strap from the engine head (which is the ground from battery) to the fire wall (body). Clean all contacts and use dielectric grease at ends. I see no reason to set grounds to master cylinder.

Thanks , I will pick up some dielectric grease . This car did not come with a engine to firewall ground strap . I went to the MC bolt because i wanted it on a solid firewall bolt , and i didn't want to drill any new holes .
 
Thanks , I will pick up some dielectric grease . This car did not come with a engine to firewall ground strap . I went to the MC bolt because i wanted it on a solid firewall bolt , and i didn't want to drill any new holes .
The hole for the ground should already be there. Passenger side by the heater hoses.
 
I put in a used swap meet alternator . It seems to be charging normally right now . At first , it was still overcharging . After twisting the wire connections , below the steering column , during a test , it went to charging normally . I will chase that later . For now , i want to fix chase possible bad ground .

The headlights and front turn signals don't light up . With the headlight switch on , the side marker lights , the fender mounted turn signals , the directional and high beam indicators in the dash , all light up solid . With everything connected , the foot dimmer switch is getting power to all three terminals . About 7 or 8 volts each . The headlight terminals are only getting 0.18 v .

I have cleaned up the grounds on the radiator support , the block to battery cable , and the block to firewall strap . Is there a way to test the grounds or the wires ? Are there any more grounds for the headlights ? Does the starter cable connections have anything to do with that ? One of those looks somewhat corroded at the connection .
 
I put in a used swap meet alternator . It seems to be charging normally right now . At first , it was still overcharging . After twisting the wire connections , below the steering column , during a test , it went to charging normally . I will chase that later . For now , i want to fix chase possible bad ground .

The headlights and front turn signals don't light up . With the headlight switch on , the side marker lights , the fender mounted turn signals , the directional and high beam indicators in the dash , all light up solid . With everything connected , the foot dimmer switch is getting power to all three terminals . About 7 or 8 volts each . The headlight terminals are only getting 0.18 v .

I have cleaned up the grounds on the radiator support , the block to battery cable , and the block to firewall strap . Is there a way to test the grounds or the wires ? Are there any more grounds for the headlights ? Does the starter cable connections have anything to do with that ? One of those looks somewhat corroded at the connection .
After checking the grounds (I use a OHM meter at the ground connections, to be sure you are getting a 100% continuity) Example: ground wire to body or "-" on battery. Next I would remove the firewall electrical plug at the block (a known problem with these older cars) and clean terminals and again use dielectric grease. Check the AMP wire (should be the largest wire) for any burning and replace if needed. Make sure the connections (nuts) are tight at the AMP gauge.
 
Chase the ground for the headlights where it attaches up front, to the rad support, wherever. The harness will come out of the lights, and at some point will be an eyelet and screw. "It might pay" to pull a headlight out so you can access the terminals. Suspect the bulkhead connector again for voltage drop. Check the dimmer switch. Path is headlight switch, power to dimmer, select high or low, those wires through the bulkhead, and out to the headlights.
 
You can go around with the light switch on and feel the connections (even at the firewall junction block), back of the headlight switch etc. If you find a connection that is hot not making good contact, then that is part of the problem.

With the light switch on , i felt around the places mentioned above and more . most were not hot . The only place that felt hot was at the headlight connector , behind and attached to the headlight . some heat there . drivers side . i could not get my hand behind the other one to check that .
 
Check the dimmer switch.

I am confusing myself here . All 3 dimmer switch terminals have power to them at the same time . I thought that they should only have power to two at a time . Does that condition point toward anything ? All 3 terminals also had power with the dimmer switch removed . I did try a new dimmer switch i have as well . same result .

I did try to pull a headlight , but one of the screws for the bezel is stripped . i will get creative with that soon .
 
Yeh the dimmer is a SPDT switch, so one terminal receives power from the light switch, the second feeds off to the dash bright indicator, and out the bulkhead to the high beams, and the third feeds out to the low beams. You are correct==2 at a time.

IT MAY BE that the lamps are not GROUNDING, which would feed "evident" power back on the unused line. The way to find out is to turn on the lamps and measure at all three lamp terminals. Only one lamp terminal should be hot at one time. Unplug both lamps and see if the "3rd wire" goes cold
 
I don't now what this means either . With the car running , headlight switch OFF , and either turn signal on . The outside front and rear turn signals light and blink as they should . However , all four side marker lights , both fender mounted turn signals , and both signals and high beam indicator in the dash , all blink along with them at the same time . can that be the same issue ?
 
"Maybe." What have you done to check grounding and do you understand how? You HAVE to get access to the lamps and sockets involved. "Let's say" the headlight grounding is poor. The ground leg of both filaments in the headlamps are common, so if the lights are powered on to either hi or lo beam, the ground common will feed power back into the unused filament and appear with your voltage checks
 
IT MAY BE that the lamps are not GROUNDING, which would feed "evident" power back on the unused line. The way to find out is to turn on the lamps and measure at all three lamp terminals. Only one lamp terminal should be hot at one time. Unplug both lamps and see if the "3rd wire" goes cold

I finally got to the lamps and sockets . With lamps loose , but attached , all three terminals on both headlights had power at the same time . They all lit up with the test light . After unplugging both lamps , the "3rd wire" at the dimmer switch went cold . With both lamps unplugged and headlight switch on , I was seeing 6 to 12.30 volts at the top terminal of the headlight socket . 0.20 - 0.30 on one of the side terminals and 0.00 - 0.03 on the third . It was about the same for both sockets .


What have you done to check grounding and do you understand how?


i do not know how to check grounding . all i have done is cleaned up the ground where the wires connect at the radiator/support . just to bare metal as best as i could . Same for the negative battery cable end at the block .
 
Ok , so i youtubed checking grounds and everything i checked , tested good . I had however suspected the eyelet where the grounds connect to the rad support . Even though it tested good . So , i went ahead and cut it off anyway . i just did a quick stripping of the wires , and just put the bare wires where the eyelet was . Sure enough that was it . All headlights and turn signal lights , etc , are working great now . I will get the proper connectors tomorrow and wire it right .

Also , as far as the intermittent voltage drop , i have just temporarily bypassed the car's wiring for now . I bought a Voltage Regulator Connector from advance for 9.99 . and 2 pack of clamps . i have wire here . i wired the connector to two long lengths of wire . the "top" "blue" wire got connected to a clamp and is clamped on the positive battery cable . the "side" "green" wire , i put a female connector on the end . Then connected that in place of where the green wire connects to the alternator . this is just so i can drive it until i find time to start hunting for the voltage drop that was causing an overcharge . Just put it on here in case it helps someone . So far the "rig" is working good , but , i don't know if it can harm anything running it like this . As per a post i read , i did this first with just alligator clip leads , just to test the VR . that worked very good , i just wanted something more substantial to feel comfortable driving the car .
 
If you have power on all three headlamp terminals, YOU HAVE a grounding problem. That is one way to check for poor grounds. If the part/ wire/ terminal has power on the ground terminal it when powered up then it is NOT grounded
 
Just thinking,,did you check your battery status?
I had a problem with my Harley(59) when putting a Voltmeter between Ground and ?terminal on battery, the meter was all over the place,,put in a new battery, all well...
 
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