I had the same problem with my 91 W350. After about 15 years of good service, it started over charging, burning out voltage regulators a couple a year, and alternators too. None of the forums had the answer, but it’s a common complaint. After years of unsuccessful attempts to fix it, I just learned to live with it. I had to replace the multifunction switch in the column, the high/low beam part failed, and I also replaced the start/run switch in the column at the same time. As a result, I was able to switch my headlights between high and low, but as a bonus, my pulse wipers once again worked as they should, and my charging system has been rock steady at 14.2 volts for years now! Contrary to the Forums, not every problem can be traced to bad grounds. Since I replaced two things, I can’t say which cured the charging problem, but since your truck doesn’t have a multi function switch, I’d look at the ignition switch.
My 1965 Plymouth Valiant is doing the same thing. I have good grounds brand new Regulator brand new 60 amp alternator. it does it at idle but seems to smooth out with more RPM. My other car i have set up the same way with no issues. Im thinking it is hidden in a wire or ground that i cant see. Electrical gremlins sure are fun to fix.
I’ve eliminated this problem on numerous vehicles by running grounds from battery to body in several places and check the ground from firewall to engine ( found that missing too many times!) hope it helps.
Mine did the same on a dodge neon, the exterior and interior even the lights on the cluster will do a pulse and it turn out to be the both wires where you attached to the device, it seems that they are loose from factory so i just had some pliers and crush them a little bit until i had a firm connection and the pulse went away.
I have a 1978 d150 4x4 noticed that the two post on the amp meter were loose and one was getting really hot so I took the two wires off the amp meter and just connected the two wires together ditched the amp meter and put a volt gage in and my volt gage did exactly what yours was doing a couple hours later of going through the wiring and not finding anything I decided to change the volt gage out with another one and problem went away but doesn't mean that could be that simple for everyone else.
you can get a Liner voltage regulator for the volts you want, it goes in the wire. and will smooth out the voltage, or you can get a Buck voltage regulator and it will also drop and smooth out the voltage.
IIRC the timing cover is the same, its your pump that is thicker at that mount. Go to a Denso 130A internally regulated alternator off a Minivan. They are smaller, with more power but need a V-belt pulley.
I have the same problem with my '82 D150. I think that the voltage fluctuation (+/- .5 volts) from the alternator at idle is killing my voltage regulators. The fix I'm looking at is to upgrade to a 120 amp Denso alternator that is steady at idle. My ammeter and bulkhead connector are already bypassed. What did you do to fix yours? Thanks!
In the end I had replaced everything and rewired the whole system. Multiple auto zone regulators didn't fix it and I bought a high dollar Mopar unit on a whim - for me that fixed the issue! I can send you the part number if you think that'll help you too! I hope you've already got it fixed tho!
@@winterturtle5764 Sounds like you figured it out, I was going to say, most of these problems are from the low quality replacement parts. Even if you can find US made old stock replacements you're going to be much better off. I had some problems with current replacement regulators too. The OE replacement parts always worked fine. BTW, that Transpo part is made in China. I think there's a Denso Mopar alternator that's a virtual 'bolt-in' for the stock Mopar alternator. I like the Denso's and the GM/Delco alternators. They have nice wide rotors that put out near full output at idle. That's the main problem with that Mopar alternator. It's got a really narrow rotor so you can only do so much at low rotation rpm. Usually, they'll use thinner gauge wire on the field windings to increase the output, but that tends to increase the cut in or charging RPM.
You'll need to find your wiring diagrams. In the 60s and 70s and early 80s the changes were minimal so the core system is probably the same as a 60s / 70s 2 field wire external regulator alternator circuit. See if these trace like your setup. Its likely. www.mopar1.us/charge.html
It drove me nuts for years and best I can figure it was a combination of factors. I did finally get it straight though. I'd be happy to talk with you if you wanna exchange numbers in direct messaging. Either way good luck!
@@winterturtle5764 Hey! Pray do tell! :-) Now, I wonder, if I changed my gauge, would it waver, too. Mechanical meters have inherent damping (coil/inductance) and there may be some designed filtering in them. But, your Bosch gauge is newer tech and may be most accurate. Thanks.
@@winterturtle5764 971 707 5211... 79 360. In a 81 dodge sportsman.. new alt. New regulator.. and yet 15.2 v at battery... would live to get some info.
@@stuckinmygarage6220 evening friend - still having issues? I can't say I'm the authority but I've gotten my old Mopar trucks straight by a couple different methods and I'd be happy to help if I'm able!
@@winterturtle5764 Thank you, Winter Turtle. I don't think I have the issue - just curious. I have the stock 60 amp and late model regulator and simple alternator dial. It does a little shake at idle. It's what i remember as a kid in the mid '60s. No bother to me. I think u posted a video? I'll check it out. Thank you for your kindness. ☺
Did you figure anything out? Mine is doing the same thing. New alternator, new battery, new external regulator and now charging 18 when it was 12 before a new alternator.
Try running a ground wire from the back of the regulator to the battery. Im sure it will stop the over charging. If it does stop it, you have a loose or missing ground somewhere
Same issue with my '71 Dart Swinger. In dash ammeter very erratic and lights visibly change in brightness. Currently have a parts store regulator. Have added additional grounding, but did not fix. Will swap in a factory Mopar unit.
All of these voltage regulators have issues with the ground wires. You have to ground the wire BEHIND the voltage regulator,not in front. Even the manufacturer will tell you this. And make sure all your other ground wires are new and a heavier gauge wire
That sounds like a bad ground or a bad wire in the harness to me. Have you continuity checked the wiring while bending it a bit & made sure you have a strong ground?
@@winterturtle5764 If the voltage is going that high then the alternator is full-fielding. Check that the field wires are good and not cracked or grounding anywhere. Bad brush holders can cause this, too, but if you replaced the alternator that eliminated that possibility.
I will explain it to you sir what you see is back charge if you have any where a capacitor/condensor like stereo equpment you will experiance a amplified spark ignition similar to waste spark ignition! your alternator will charge only a higher rpm around 2000 2500rpm I experiance the same isue I use plazma ignition on my car lot smother engine but the thing is the idel speed is so low because of that hoter spark that my engine almost act as a disel engine see if you disconect your stereo radio and other staff perhaps it goes away I done that on porpose to my car used ceramic capacitors for a short time on positive post ignition coil to ground chassy directly used a fhew inline hv ceramic capacitrs around 12kw ich rated I got the same result thats good your engine experiances dual ignition bether economy but it goes away when you put it on baterry charger that baterry it will go back to normal and remove any capacitor ore supresor if you finde one in your car that asolation comes from static if you have a daschboar volage regulator that culd by a sorce of trobel to ore just put a diode on the alternator terminals it will stop doing it in worst case that non regulated frequency culd make engine run on isues bevare on your gages static gives false reading you shuld have a manual cooling fan switch ready because that static destroys senzors and polarity sensibel devices well rost and moisture is a bitch to electronic devices even spark plug wires I wuld sugest spray for moisture and heat protection on all important wires iven to insulate spark plug wires and not let the tuch the hood of the car arking never helps and perhaps add on those old cars heater to block ore oil fuel heaters a valve to intake manifold to draing condensed water when you not useing your truck but mostly I wuld sugest oil and fuel adutives those old trucks dont like non leaded fuel that baterry of yours act more as a capacitor then a baterry high potential but no amp 😞 perhaps you shuld see how modife alternator out put modification on low speed perhaps a tractor alternator culd do that job ore simly use a solid state old school voltage regulator those you can varie amps and volts but still use diodes to prevent back charge
Hey man I have 1975 Dodge pretty similar to your 76 , I'm curious how you wires up the internally regulated alternator. My truck overcharges. Goes up to 18 volts , yikes, I've tried several regulators , fixed wires etc haven't fixed the issue , thanks if you can help me out
Heres a link to a quick and dirty overview of my wiring mods. Post again if you want any other info on it. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Os_KADJDM0k.html
@@rogerburns9960 I found the best way is to use GMs system with the one wire, it simplifies you’re harness and in the end it looks cleaner anyways than original.
I forget where I was when I took the video but I did eventually succeed. In my case a new Mopar OEM brand regulator unit with a high quality ground solved my problem. I'm happy to help if you have more or different questions!
@@rogerburns9960 in the end I got mine right by grinding and cleaning the grounds (dielectric grease helps make it last) - verifying all my wires and connectors were good - and buying a real Mopar regulator. The auto store replacements are badly calibrated and give me a rhythmic fluctuation at times is seems.
print and perform this voltage drop test i.imgur.com/kviX0VQ.jpg perform additional voltage drop tests. beween the engine block and the voltage regulator body.. do the same test between the engine block and the ignition module also.. here is a diagram of the mopar charging system.. i.imgur.com/3sgmufP.jpg post a reply listing the results of your test.. since you don't have an underhood fuse box.. use the battery stud on the starter relay for test 5.. please perform all six steps..