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B300 won't charge battery.


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Deadman2098
Novice

Oct 28, 2020, 11:30 PM

Post #1 of 14 (173 views)
B300 won't charge battery. Sign In

I have a 1979 Dodge B300 360 v8 5.9 l 2 bbl and it's not charging the battery. I've changed the voltage regulator, the alternator, battery isolator and positive battery cable. The battery is new. I've had a guy come who checked wires and all seem to be good. The weird thing is that when the battery line from the alternator isn't hooked up it gives 50 or more volts. When hooked up to the battery isolator it gives 4.8 volts or less. Disconnect the voltage regulator and it gives .1 or .2 volts. So the regulator it sending a signal to the alternator. But it putting out to much power one way or not enough.

Any suggestions on causes would be great.


(This post was edited by Deadman2098 on Oct 28, 2020, 11:39 PM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Oct 29, 2020, 2:12 AM

Post #2 of 14 (156 views)
Re: B300 won't charge battery. Sign In

50 volts? How is that even possible?

Where are you measuring this? Have you tested all your fuses with a test light?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Oct 29, 2020, 2:55 AM

Post #3 of 14 (152 views)
Re: B300 won't charge battery. Sign In

? Is this a real "Dodge" truck? Engine would match. The OE charging system on those were pretty straight forward - regulator on firewall, plug and play unless all loused up. Sure cables, wires, plugs and battery all have to be in shape redone or cleaned up known good first. Type of "disconnect" is in question IMO either NG or IDK but you get 100% or that isn't right at all. Those sold anywhere still get better or easier one - brass now best.
Get some real readings those mean nothing are impossible as HT said you don't really need more than a voltmeter and test light for a '79 much of anything,
T



Deadman2098
Novice

Oct 29, 2020, 7:36 AM

Post #4 of 14 (142 views)
Re: B300 won't charge battery. Sign In


In Reply To
50 volts? How is that even possible?

Where are you measuring this? Have you tested all your fuses with a test light?


Directly off the wire for the battery from the alternator. As I said that what it reads when it's not connected to the battery isolator. I had a guy who came and used his multimeter to try to figure out what was wrong. After seeing that reading and even higher, I think 56 volts may have been the highest, I don't run out for very long when trying that same test. He thought it was going to be the alternator which was new. I had to wait for the following day to take it out. The battery wire was still disconnected and I had to use my van to go to work since it is my only vehicle. When I got the alternator out I noticed part was cracked and slightly burned. When Orielies, where I got the alternator from, tested it, it tested as good but they gave me another one because of the damage. So it was replaced under warranty. But it still does the same thing. I used a multimeter to do the test the same way the the guy I mentioned did and got 50 volts. I didn't run it for very long. Just long enough to get that result. When I told him about it he said it doesn't make sense.


Deadman2098
Novice

Oct 29, 2020, 8:17 AM

Post #5 of 14 (132 views)
Re: B300 won't charge battery. Sign In

? Is this a real "Dodge" truck? It is a camper van and it is very real. The manual indicates from 70 to 72 the the wire that goes to the regulator connects to the terminal furthest from the battery line. Newer ones to 79 the same wire goes the terminal closest to the battery line. On the alternator neither FLD terminal is labeled as anything other than FLD. No positive or negative label and I've tried it both ways. Looking at pictures for other brands for my van shows the same thing. I have tested the wire for ohms and they test fine. No resistance shows. I have also cleaned connections. I've done everything I can think of after looking at YouTube videos for ideas. Nothing makes any difference and it's getting very frustrating.https://drive.google.com/file/d/1CEKIiZDDmW4q3jHaXUc2C2_AiL0tQz0r/view?usp=drivesdk


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Oct 29, 2020, 8:50 AM

Post #6 of 14 (124 views)
Re: B300 won't charge battery. Sign In

It's a real Dodge just custom likely for being a camper now was an objective of Chrysler for truck lines with chassis back that far. IDK if you have mixed up any inverter in reading things if 110 A/C current can go inside camper that's not what you want.
12V system would be maxed at ~14.8 regulated can't go much higher for alternator would explode if let run and burn it out but this worked? 50V isn't a reading for either so IDK who's check where.


This alt may not be the one I'm thinking of used in everything could replace brushes with it still mounted probably has two belts to it?
Battery just charged and sitting there NO lights on even a hood light. Should read about 12.6V, check that. If started would jump to 13- 14.8 within fractions that close or a problem. If you can (camper wires must be a show in this) follow backwards from regulator to alternator it's messed up somewhere if not charging that is a broken wire or wrinkles of a fusible link will be seen - look around it's a camper they do who knows what to make those Dodge just made the truck no alter to what it would be,


T



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Oct 29, 2020, 9:47 AM

Post #7 of 14 (119 views)
Re: B300 won't charge battery. Sign In


Quote
directly off the wire for the battery from the alternator.


Are you testing at the alternator end of this wire or the battery end?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Deadman2098
Novice

Oct 29, 2020, 10:20 AM

Post #8 of 14 (117 views)
Re: B300 won't charge battery. Sign In

To get the 50 volts reading I disconnect the battery line from the battery isolator. I put the red probe from the multimeter on the battery line and the black wire on the negative terminal on the battery. I once tried it on the positive terminal and it gave me 40 volts. Before it started giving me trouble the voltage would be 14.5 till I turned on headlights then it would be 14 to 14.3 I think.

Currently when fully charged the battery reads 13 volts. That drops by .3 or .4 when I start it. When ever I go anywhere, when I get back I take the battery out and charge it so I know I have enough power to get around town.

Using the ohm section of my multimeter I put a probe in the end for a green wire from the regulator end and the other prob on the other end of the green wire. It shows no resistance. 000. The red wire goes to a resistor on the firewall and I check it the same way and got the same result. I believe the guy who was trying to figure out what was wrong probed the wires and found everything was working. I don't know what else to do.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Oct 29, 2020, 11:12 AM

Post #9 of 14 (107 views)
Re: B300 won't charge battery. Sign In

Easy to do but I'm confused: Quoting what you just said>
>>"Before it started giving me trouble the voltage would be 14.5 till I turned on headlights then it would be 14 to 14.3 I think.

Currently when fully charged the battery reads 13 volts. That drops by .3 or .4 when I start it.<<"
That's what to expect EXCEPT when you "crank" it, before it starts volts will drop not "point 3 or 4" closer to a couple volts as cranking is the load except this is a camper so other things should be off when just starting engine.


What type of "battery" isolator" do you mean? As in you disconnect this battery totally when the camper isn't used perhaps use 110 plug in power from land? The two things can mean different things like automatically switches both A/C + D/C items in camper to 12V when you unhook from "land" power or should be doing that inside units or shut all off??


I can't speak for more than isolating the battery as in like it just sits in there disconnected to maybe save it from other things drawing on it. Those IDK what you have, multiple batteries isolate that one from other ones or just unplug that one? Dial switch or leaving a cable undone? Assorted types used depending on the "camper" part??
Just alternator should behave as you said and now doesn't read properly nor charge the battery. I kinda think since it can work out of vehicle tested that this ''ISOLATOR'' is messed up?
OTHER AND IMPORTANT: Don't leave a cable off battery and run engine if that battery is for that engine running the alternator. That's damaging or confusing to alternators, voltage spikes but not this much. Just don't ever run an engine with an alternator without the battery hooked up is what I'm saying that's possibly the reason now it screwing up.
A/C - D/C: Alternator is A/C inside is making D/C before it leaves thru diodes inside it. Don't confuse Alternators with Generators none known for engines in vehicles for this old even lots older,


Tom



Deadman2098
Novice

Oct 29, 2020, 11:42 AM

Post #10 of 14 (104 views)
Re: B300 won't charge battery. Sign In

Being a camper van it has a battery for starting and all that stuff. Then it has a second battery for lights and other stuff unrelated to running the van. The isolator charges the batteries isolating one charge from the other. The isolator is new and better be good.

I have never tried running the van without the battery. I take it of the van the charge it.

The battery line from the alternator goes directly to the battery isolator and from there charges both batteries. I have check resistance on the wire from the isolater to the battery and that was good.

Is there a way to test the voltage regulator?


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Oct 29, 2020, 12:35 PM

Post #11 of 14 (95 views)
Re: B300 won't charge battery. Sign In

Voltage regulator if the sealed (jelly in backside?) type: Test I always used was those needed ground to body metal so rather than dig out tons of test bull bought one new, grounded that on suspect vehicle as in "swaptronics" was done in 15 seconds either it was right or no change and move on. They used to go a lot so did alternators being exposed IMO a bit too much you could see the dang brushes in back - again if that type. Those used on 95% of stuff thru IDK '72ish till probably the mid late 80s?


There was no fix for those or ones that got hot could see burns could use the newer for pre '72 "Mopars" I'll call them.


Now this is "Truck" category with known more need or was there? I can't know what HD would have been never saw one knew all this crap new was working then a lot of assorted stuff. These were such nightmares I carried parts for them for road calls - really! Both regulator or just brushes.


None of that accounts for voltage spiking like you saw or that somehow isn't accurate.


I get it but only a little it's unique to this one not another unless you knew the "Camper Maker" always did X,Y + Z for the items in rear.
So, I'd like to see you isolate what is camper at the battery that starts the engine if your "isolator" does that?? Then hope we get a valid reading to work with 12V systems D/C current don't do those voltages - in a lifetime never heard of it? Tom
___________________________
Just ignore if you want now is why I lost hair over the isolator thing: Owned a small yacht with called "Shore Power" that knew automatically to shut off power to refrigerator, other things that were essentially "house" powered did both! Last boat had just one battery auto swapped would be dead (deep cycle marine) instead of isolating it I just put another battery down in bilge to jump start myself or use that one if a failure totally. Why? That was OCEAN friend - there ain't no road calls it was all mine or out to Sea never to be found again!
Other yachts had up to six batteries for what I also worked on those did isolate so many so you could run lots and still have a few left! Yikes - TVs - ice makers, full size refrigerators, powered running water etc. Twin engines get one going, wait and charge batteries so get the other going if all FUBAR - other's boats (houses on water) not a one the same as another. All were twin everything but could work 100% on just one or the other LOSS OF HAIR to figure out a problem!


Point is OMG got an education in what was supposed to be time off from this crap! The engines were gasoline automotive type used "Mopar, GM, and Ford, small or HUGE block beasts just made for marine slight differences - no air filters for example.


Same idea I'm guessing for campers just not twin engines in this or HUGE just not done. A second for a generator YES I don't thing we are talking that I'm out couldn't fit those anywhere I ever worked.
Back to basics you said can and do run just engine on this find regulator unhook that if you want or feel if it gets a bit warm quickly I default IDK how to test one but it's grounding field in gradients of need is the whole idea for alternators any brand or type of machine or vehicle,


Tom again...…..



Deadman2098
Novice

Oct 29, 2020, 1:01 PM

Post #12 of 14 (90 views)
Re: B300 won't charge battery. Sign In

Well I just got a 12 volt circuit tester. You know with the clamp and prob that a hitman could use? I'm going try that thing and see what I find all I know for sure is this thing is driving me nuts. So I'm just reaching out to anyone anywhere I think I can find help.

Thanks for the info. If all else fails I'll use that tester to stab myself in the eye to distract myself from the irritation of trying to figure this thing out.


Deadman2098
Novice

Oct 29, 2020, 2:11 PM

Post #13 of 14 (83 views)
Re: B300 won't charge battery. Sign In

I think I got it fixed for now. I disconnected the line for the house battery. Now the battery line before the isolator now gives 15.8. At the battery it reads 14.7. So it's a bit higher than normal. But it's still good I think. At least it's not really low.

It's your talk about boats house batteries that made me decide to try that.

Thanks for the help.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Oct 29, 2020, 2:31 PM

Post #14 of 14 (76 views)
Re: B300 won't charge battery. Sign In

Quote last post ">Now the battery line before the isolator now gives 15.8. At the battery it reads 14.7. So it's a bit higher than normal.<"


Just that bit! There must be something spooked (no Halloween joke) with that isolator? How can one wire read like that when closer to isolator than the battery? It's getting feedback from the stars or something??


BTW - you can't run long at a real 15.8 it will blow things - not a guess it will - bulbs first then more at even that.


Test lights!!! You need both types of those you described, one incandescent and another now LED is safer for electronic things. Been freaking decades sport - teacher in OMG who knows how long ago with a light bulb made a voltage regulator in a jam but has to be incandescent is all there was. The wattage of bulb could fake it in a jam if just to get home, destination.
Don't quote me or do this without confirmation as I'm not sure! I think if you found a dead two prong Mopar voltage regulator you could use a bulb socket and connect both stripped ends of wire with a bulb or your test light and get a reaction that would conclude that's where the problem is? Don't THIS HAS SOMETHING TOTALLY ELSE TO GIVE YOU THE LAST READINGS GOING ON!


IDK and don't want you to make it worse but now not thrilled with isolator or something about it or nearby?? Good luck, I think you'll need it! Tom






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