68 Dart Voltage Reg "issues" - Where is factory mounting location

-
Theo

Theo

Member
Joined
Nov 24, 2017
Messages
18
Reaction score
2
Location
Albuquerque, NM
I've been working on a voltage regulation issue - 16.5 volts at the alternator stud and elsewhere. I figure that the voltage reg is bad because if I ground out the field wire, things settle down immediately to 12.8 volts (new battery). Anyways, I was trying to decide what brand replacement to by and started looking at Dart engine bay pics online - none of them seem to have the regulator mounted where mine is - high up on the drivers side firewall, just above the ballast resistor. WHERE IS THE REGULATOR SUPPOSED TO BE MOUNTED - FACTORY CONFIG for a 383 GTS ? Could someone send me a pic ?
 
No pics for you, but the last time I dealt with one of those style regulators on a 69 B body the replacement was a solid state unit that fit underneath the stock can. It was on the firewall near where the wiring harness block goes through the firewall, on the two stamped raised channels in that area.
 
Before you condemn the regulator take some measurements. OFTEN the problem is voltage drop in the harness

1....With engine stopped and the key in the "run" position put one probe of your multimeter on the regulator IGN terminal and the other on the battery POS post. you are hoping for a very low reading, the lower the better. More than about .3V (3/10 of one volt) you need to find where the drop is. Firewall bulkhead connector, ignition switch connector, in the switch itself are a few popular problem areas

2....With the engine running at simulated "low to medium cruise" RPM take the following readings first with all accessories OFF, and again ON, headlights, heater blower, etc

Stab one probe of your meter into the VR mounting flange. Stab the other into the battery NEG post. As with 1 above, the lower the better, zero is perfect. Make SURE the VR is solidly mounted and grounded. Scrap around the mounting bolts, and use star lock washers
 
20161002_163802.jpg
 
67Dart273 said:
Before you condemn the regulator take some measurements. OFTEN the problem is voltage drop in the harness

1....With engine stopped and the key in the "run" position put one probe of your multimeter on the regulator IGN terminal and the other on the battery POS post. you are hoping for a very low reading, the lower the better. More than about .3V (3/10 of one volt) you need to find where the drop is. Firewall bulkhead connector, ignition switch connector, in the switch itself are a few popular problem areas

2....With the engine running at simulated "low to medium cruise" RPM take the following readings first with all accessories OFF, and again ON, headlights, heater blower, etc

Stab one probe of your meter into the VR mounting flange. Stab the other into the battery NEG post. As with 1 above, the lower the better, zero is perfect. Make SURE the VR is solidly mounted and grounded. Scrap around the mounting bolts, and use star lock washers
Click to expand...

Thx, I'll give those a try tomorrow.
 
Theo said:
Thx, I'll give those a try tomorrow.
Click to expand...
Meas #1, Battery + to the Vreg Ign term is 1.0 V, so I do have a drop in the harnessing as you suggest. Meas #2 Batt - to the Vreg frame is 0.0 V with no accessories on and 0.1 V with all accessories - so I have a good ground.

I'll search for my voltage drop in the harnessing. I've seen some articles that point fingers at the firewall bulkhead connector as the usual offender.

One question though, If I do a temp wire bypass from Alt stud, directly to the Vreg Ign terminal that should bypass the bulkhead conn, ig sw, etc, etc - and if my Vreg is OK, I shouldn't be seeing the 16.5 v readings anymore - it should drop down to 14 v or so, correct?
 
Further investigation into the voltage drop showed that Pin J (+12V fusible link run from battery) and Pin P (Alternator Output) on the firewall bulkhead connector had gone high resistance and started melting the bulkhead connector. To make things even worse, a mickie-fix was done to the alternator output leg under the dash with a butt-splice and it wasn't even soldered.
Some searching online yielded a "reasonably priced source" for a new bulkhead connector, mating engine harness connector, and a handfull of replacement contacts. Source was Bill and Rosie Evans of Evans Wiring Harnesses. What nice people, Bill spent time with me on the phone giving suggestions - On a Saturday afternoon no less ! He's got my business in the future on anything MOPAR/Electrical !

IMG_20171125_143058073.jpg
IMG_20171125_151418499_HDR.jpg
IMG_20171125_151508530_HDR.jpg
 
A temporary bypass you should go from battery to V reg IGN, and that should give you the proper charging voltage if regulator is good

Please read the MAD article even if you don't do the mod the way they outline it. The "big problems" in these old girls is the bulkhead connector, the ammeter and it's connections, the ignition switch connector and the switch "sometimes"

Catalog
 
Thanks 67Dart273. That MAD article hits my problem dead center. I will consider doing the mod, and adding a voltmeter in place of the ammeter as some have done - if I can find a voltmeter that looks more at home in the dash cluster than this one does. It's a great idea, but I'm trying to maintain original look. Maybe there is another MOPAR vehicle that has a voltmeter similar in styling to the other gauges. I'll have to spend some time looking.
upload_2017-11-25_20-21-57.png
 
There is an old thread you can converter that ammeter to a voltmeter and keep it looking VERY close to stock........that is you use your old ammeter scale, and use the middle mark for the 14V point

Read through this, there are several types of clusters discussed

Ammeter to Voltmeter...who does it?
 
You can do that. Or you can keep the ammeter once you've cleaned everything up and tested to make sure there's no voltage drops. The meter itself isn't the big offender - its all the connections and crimps that develop resistance or get loose. On a stock A-body, the one really weak circuit is the headlights. In addition to all the connections and long route, the wires are 1 size smaller than B and E bodies. :(

If you do decide to bypass, there are other ways to do it than MAD's. Rob ( crackedback ) and others have posted about that.
 
Mattax said:
The meter itself isn't the big offender - .
Click to expand...

No, "it's the meter." There are many internet photos to prove this. The problem is the guts of the meter, the "shunt" is held to the studs only by means of the "sandwich" of the nuts, insulators, and other parts. The studs are "loose" from the shunt otherwise. The very photo at the MAD site is one I've seen many times.........typically a 70's Dodge pickup which has a winch, snowplow lift, or other big accessory. The dash cluster is PLASTIC and when the studs/ wire ends/ etc warms up a bit the plastic softens, it all gets loose and snowballs (fireballs?) from there

amp-ga19.jpg


I do not specifically support the MAD mod per se, but it IS a way to go. IF YOU ONLY add a jumper and do not fuse/ protect it, you have REMOVED fuse / fuse link protection from the harness. Keep that in mind.
 
Almost every one I've seen on mopars and jeeps are actually not in the meter, and I'm not the only one. It's poor connections, almost always combined with something else - such as chafed wire insulation, overloaded circuit, or an "I'll just drive it a little further" or subsitute a wire for the fusible link even though meter is pegged.
Its also easy enough to check to see if there's a problem. In this instance, there's nothing to hint at a problem with it. A lot of people read MAD and think all of the power goes through the ammeter. That's only true when alternator isn't providing power.
The trouble spots I see, especially on A-bodies, are the bulkhead connectors and headlight connections including at the connector on the switch.
 
Mattax said:
Almost every one I've seen on mopars and jeeps are actually not in the meter, .
Click to expand...

Well then you have not seen much. **** the ammeter in my 70 RR failed CLEAR BACK IN THE EARLY 70's. AND IT FAILED FROM THE EXACT REASONS I DETAILED ABOVE. The plastic dash housing in which it is mounted "gave" a bit and the studs got loose, and then that looseness caused the studs/ shunt to heat up and MELT the plastic.

The thing you cannot seem to get through your head, here, IS THAT THERE ARE SEVERAL CAUSES of problems in Mopar systems AND THEY ARE CHRONIC

I am not going to argue with you whether the bulkhead connector is so much percentage "more likely" to cause problems than something else. I'm old. I first fixed a major problem in a Mopar in about 1971. This was a failure of the welded splice in my friend's 69 RR. I had the entire dash torn apart in the parking lot of his apartment complex and HE wondered if "we" knew what we were doing. I told him "it has to be in here somewhere." And it WAS.

Since that time I've seen the terminals on the ammeter wires fail for no reason other than "they failed." Intermittent. Lots of bulkhead problems. Somewhere around 8 or so failures of the welded splice. LOTS of failures in ammeter as I detailed IN PICKUPS MOSTLY with winches and snow plows.

So, I'm DONE arguing with you. What I post is what I've SEEN in more than 45 years
 
LOTS of failures in ammeter as I detailed IN PICKUPS MOSTLY with winches and snow plows.
Click to expand...
No disagreement here, or that that are multiple weak points.
A similar situation (without the shock) is when electrical devices like fuel pumps, fans and efi are added.
 
Well, like I said about my Dart.... I found a partially melted bulkhead connector, and a questionable barrel crimp lug - both in the high current paths - so you are both right. I am going to solder the studs on the ammeter (if I retain it). I remember having to do the same thing with an HVAC circuit board that had a push in stud - got hotter then heck and would shut down the system - til I soldered it into the board.
I really appreciate the help from both of you guys, saved me a lot of time and guesswork.
 
^^If you are going to insist on keeping the ammeter, I would go further. Don't just "fix up" the bulkhead connector. Either consider drilling out the black and red ammeter wires and passing wires straight through, or else make up a duplicate of the so called "fleet wiring." You will have to find this in some of the service manuals.

See, even "Ma" knew that the bulkhead connector was a problem. When you ordered the optional 65A alternator, you got what is called "fleet wiring." This may have been dealer done, I'm not sure. The ammeter was routed through a separate grommet in the firewall, leaving the original wires to just feed the interior, similar to the MAD modification.

This was known as "fleet" because it was used in police, taxi, etc "fleet" vehicles

Also by 71 or so, Ma had started using external shunt ammeters same as Ferd and GM. By 76? I have forgotten.........I believe the A bodies were also external shunt.

Here

mopar "fleet wiring" - Google Search

Here's the Satellite/ B body fleet wiring setup from page 8-167 of the '72 shop manual, which you can download from MyMopar

fleet.jpg


Notice the two wires going through the grommet near the bottom. Notice the dotted lines which are the original ammeter wires, cut and taped off

Ignore the bottom wire which is related to electric pump on some models
 
Yes, I pretty much decided to nix the ammeter last night, going with "most' of the Mad mod. I'll still retain the J and P contacts in the bulkead conn to supply power to dash, etc. But at least they will now provide a parallel path for the load current. My car isn't highly optioned (and it is staying stock in that respect), so I should be safe - and yes, there will be a fusible link in the Alternator to +Battery path. I also ordered the Sunpro voltmeter everyone is using in place of the ammeter. If I'm able to apply the existing ammeter gauge face to it (to retain the factory look/styling), the faces center bar will indicate 13V, with the next bars to left and right indicating 10.5V and 15.5V respectively, and the outermost bars indicating 8V and 18V respectively. Should be really nice and functional.
 
Yeah !!!! I finally worked up the nerve to disassemble my dash cluster, remove the Ammeter and replace it with a Sunpro Voltmeter movement - it wasn't that hard. I had done the MAD conversion discussed above (running the alternator output directly to the starter relay - so the ammeter wasn't used anymore.

I wanted the gauge cluster to still look stock, so I carefully removed the old ammeter gauge face and transferred it to the Sunpro voltmeter. I also applied the original ammeter indicator needle to the Sunpro Needle - which was shorter and a different shade of red Getting the Sunpro movement to fit the housing required some Dremel work to the movement frame - but it is all nylon or plastic, so it wasn't too hard to do.

The Sunpro gauge also has an internal trim resistor so I was able to set the center scale mark on the ammeter face to indicate 12.6V (a fully charged battery). Above the center mark will indicate battery charging, and below the center mark will indicate battery discharging. I'll have to experiment a bit with a variable power supply to see what the ammeter face markings correspond to voltage-wise.

IMG_20180106_171712695.jpg


IMG_20180106_171722000_HDR.jpg


IMG_20180106_171953280.jpg


IMG_20180106_172604641.jpg
 
I did not fiddle with the meter needle, just used the one on the Sunpro. Yours looks great.
 
Thx, 67Dart273. I think you are the one who gave me the info for the MAD mod to begin with. Now that the cluster is done, I can reinstall it and put the rest of my dash together. Since I had to loosen the steering column to remove the cluster - I went ahead and pulled it out, painted it and the floor plates, and got the correct install hardware for everything. For some reason when the car was done, they neglected the column entirely and it kind of stuck out like a sore thumb. I also added a pressure transducer and bulkhead connector wiring for an electrical oil pressure gauge. Funny how these little jobs grow and grow, but while things are apart you may as well do all you can.
 
You must log in or register to reply here.
-

Back
Top