New altenator but batteries still not charging.

[Wayfarer Malang]

I am stuck and I just can't wrap my head around it. new alternator voltage regulator and it still in not charging Battery. To top it all off I have A battery that reads 12 volts but won't turn the turn motor over. I need to leave  I have no home base and very little funds so I have to fix it my self.
Peace

[Oz]

Since batteries and charging systems are a very common issue, we do have some excellent testing guides in the Mechanics 101 section of the Member area which you can download too.   

[DaveVA78Chieftain]

If battery is fully charged (12.6VDC at rest) and will not turn the engine over then this sounds more like a starting problem not a charging problem.
1. How do you know the battery is charged?  Did you charge it with an external battery charger?
2. Do the headlights work?  If not, then check the fusible link at the starter relay mounted to the driver side frame rail outboard the bell housing.

There are several steps to tracking this down however I have to go out and work on my own rig at the moment.  I have a 4hr trip to go on next weekend I am preparing for.

Dave

[ibdilbert01]

12.0 volts would indicate a battery only charged to 25%.    Probably not enough to turn your engine over.     

As Dave said, 12.6 volts (at rest) is fully charged.   

12.4 volts is 75%
12.2 volts is 50%
12.0 volts is 25%
11.8 volts, He's dead Jim....

[Wayfarer Malang]

I have tested and retested all the out put is good. it just not going to bat some were in the dash one wire is not talking to another  what happens if i by pass it all and go from regulator to battery I al ready took out battery isolator and batteries so what happens if i rewire it and how do u find what color is what white is supposed to be ground.  oh and farm king is cheeper then wall mart on batteries. I changed my deep cycle to a battery with 700 cranking amps what ever that is and she starts better then ever. dose that mean that u should not use deep cycle to start motor? Sorry for typo need to move and am running out of time so back to work. Thanks for the replays and yes i  read all the tech section. I use a Fluke tester
Peace

[summerlin51]

Just a thought but when you put in the new alternator did you disconnect the wire at the relay start solenoid?  The charge wire from the alternator must be on the positive side of battery and not on the starter side on the solenoid. On my set up I have two solenoids, an isolator one that separates the coach and chassis batteries that kicks in when I switch it from dual / momentary  (only used if chassis battery is dead).  A second one (start solenoid) mounted on the engine that controls the starter with the S term for the start wire, the I term for the alternator, and the two large terminals that allow the current to flow when you turn the key to start. These use Ford type fender mounted start solenoids though I do think AC Delco makes the same one for twice as much. Hoping this helps. Oscar

[PwrWgnWalt]

Having just reworked my 1977 Dodge M500 wiring and troubleshooting an overcharging situation, maybe I can help some. I don't mean to sound condescending, but am going to start with the  basics first...

First:  The wiring in the dash should not have anything to do with your issue.
When you pulled out the isolator - you would have had to CONNECT the wire running from the ALT to the Isolator, TO the Chassis Battery wire coming from the Isolator.

Second:  The usual Mopar way of getting the alternator charge to your chassis/starter battery is back through the Starter Relay and your main battery cable (from the positive battery post (+) to the starter relay). The relay is a little rectangular box, usually on the inside of the frame rail just behind the starter and engine-to-transmission junction. 

Third:  There are several wires that run down there at the Starter Relay (not talking about the solenoid on the starter motor), very near the hot exhaust, and some of them contain fusible link wire... a fusible link is like a fuse, designed to 'break' when there's an overload. Except, in this case, the actual wire is smaller guage than the main wire it feeds to/from, so it will melt first and 'break' the circuit.  I know, what a PITA. Look for signs of disfigureed or burnt wiring.  Peel back the tape if necessary.

Fourth:  The voltage Regulator monitors the voltage produced by the Alternator and turns the Alternator's diodes On and Off, to produce more or less output voltage. This happens through the 2 Field connection wire at the alternator - make sure these are connected well and not grounded.

So - here come the questions - use a voltmeter and write down the answers, then see below (and post your answers/findings):

#1:  does engine start normally?  (with key)   or - how do you start it?
#2:  what is exact voltage at battery, engine OFF & key both OFF?  (xx.x volts)
#3:  what is exact voltage at battery, engine ON & key both ON?  (xx.x volts)


The voltage (Bty connected, but key/engine OFF) at the end of the battery cable attaching to the large stud terminal on the Starter Relay should be within ~0.2 v of Battery voltage (#2 above). If not, Battery Cable is bad or there's a short somewhere in that cable.

Next check the voltage on the large stud terminal itself, on the Starter Relay. Again, should be close to #2 above. If not, this may indicate one of those wires attaching there is shorting.

Next check the large stud terminal on the Alternator. It too should be Battery voltage. If not, the RED(?) wire (it's probably a fusible link) coming off the Starter Relay and going to the Alternator is bad.

Now (IMPORTANT - engine OFF; but key "ON") check the electronic voltage regulator connector plug (triangular plug, with maybe a Red and Light Green wire?).  The voltage for each terminal on the plug should be the same as #2 above.

Let me know what you find... these tests should isolate the issue.
- Walt

[ibdilbert01]

dose that mean that u should not use deep cycle to start motor?

Your not suppose to, as a true deep cycle battery is not designed to deliver the large cranking amps required by your starter. 


That being said, most deep cycle rv batteries sold in the large box stores are more of a hybrid design.  You can safely start off these, as long as their cranking amps are the correct rating for your needs. 


A really simple way to make sure your charging is to do a simple voltage test while the rig is running.   Check the battery voltage and as long as its ~13.5 or more, your charging.   

[Wayfarer Malang]

Thank you I will check all this and you'er not condescending To someone thats trying to learn and believe me this girl needs all the help she can.

So is this why my dash amp gage is not working as well?

I will go back to the starter thingy to day. The other thing is were can i find a wiring I guess its call diagram with the Winnebago wiring and Dodge and how that interconnect. it talk about another manual in the Dodge service Manual.

Hugs

[PwrWgnWalt]

If I had to guess (just a hunch) - here's what I think:

The wire running between your starter relay and alternator is 'broken', probably at or near the starter relay (which may likely be either the fusible link or something not connected properly).  The tests I wrote about above will hopefully diagnose it.

Why do I think this? 
1. As mentioned above, the positive batery cable (+) comes to the starter relay (stud terminal), then to/from the
    Alternator from there (on mine, via a 14 ga. Red fusible link, to a 10 ga. Black wire going to the Alternator "BATT"
    connection stud).
2. The Ammeter wires (18 gauge black, and 18 ga. red on my '77) both come from that Alternator wire (close to the
    starter relay, right after the fusible link), so if the Alternator wire is broken between the power source (Starter Relay
    stud) and these wire junctions, the Ammeter won't get current flow and won't work. 
3.  If this is the case, chances are most of the rest of your stuff won't work, either (interior lights, heater, and other stuff
     powered from the Dodge fuse panel). 

Oh - and be sure to trace what you did when you removed the Battery Isolator (see the "Basics - 'First'" section above).

Will await your testing results...
- Walt

[DaveVA78Chieftain]

74-75 Chassis wiring diagram available for download from links at top of page:
Members Area
Manuals, diagrams, and Tech Info
Coach Owners Manuals - Dodge
Scroll down to Chassis & Coach Wiring, 74/75
Select All Chassis link from Chassis wiring column.

My suggestion to start is:
1. Charging circuit useless if engine will not start so work starter first
2. Battery fully charged? (12.6VDC)
3. Lights work? (checks fusible link) - measuring voltage say at alternator B+ post can fool you as it need to be under load to check it.
4. From there one needs to work through the starting circuit.  Battery - Starter relay (large post) - ignition Switch - starter relay - starter.


Manuals - She needs
Dodge Service: 69-73 Service plus 74/75 supplement  (her wiring diagram is in the supplement)
Dodge parts: 69-77 version

Dave

[Wayfarer Malang]

Yea I have all that mark thank you do you have a manual that interconnects dodge with winnebago wireing?

[Wayfarer Malang]

Well i went over it all agin and still can't find it. it fires with one turn of the key with out using gas pedal traced wiring from starter to dash. checked alt and regulator agin for the umpteenth time so  take the dash apart? run a wire and by pass the sister and go to bat? I am lost went from stater to dash.
Omg  Hm? Peace

[ibdilbert01]

take the dash apart?

Hold the horses for a sec.  I think PowerWagon is on the right path here.  Looking at the wiring diagram for your chassis...

Coming off the alternator you should have a black 10 gauge wire that runs over to the starter relay.   Follow that wire and make sure it goes to the starter relay.    On the starter relay is a larger lug with a nut, you need to test the voltage on this lug while the engine is running and see if its 13.5 or more volts. 

If you have 13.5 here, then you know the alternator and regulator is working, and you know the wire from the alternator to this point is good.   

Another wire runs from the same post to the battery, the diagram says its a red 6 guage, so its a much larger wire.   Because you can start the rig on a good battery, I believe this wire is not your issue. 

[DaveVA78Chieftain]

I see different things being said so I am a bit confused. Please answer one simple question.

In your last post you said: "it fires with one turn of the key with out using gas pedal"

Should we take that to mean, you can now start the motor and it is running. 

If so, then we can now progress to determining what is wrong with the charging circuit.
If not then plaese state that clearly.

Dave

[Wayfarer Malang]

Thank you for your help I am so lost. First Yes it is a charging problem.
The dash amp gage is not telling me any thing but my meter says the Alternator works so dose regulator.

Here's were I am lost So the black wire goes from Alternator to relay so what dose the regulator do turn the black on and off?

I am about out of time I have till monday to move. I have been going over this for a week now and still have no idea, the black wire has no current so if I run a new black wire from Alternator to relay that will take care of it?

Thank you so much Hugs

[ibdilbert01]

The function of the regulator is to control the the current going through the rotor, this is done so the output voltage can maintain a suitable charge voltage, normally above 13.5 volts.   

"Normally" when they fail, you get 0 voltage out of the alternator. 

Have you checked the voltage while the engine was running on that black wire connected to the relay yet?  If so what was the voltage reading?  Also that wiring diagram shows a fuse-able link in between the alternator and the relay, if its blown, you will not be charging.   

Something to think about, if your getting 13.5+ volts on your battery terminals while the engine is running, you are charging, regardless of what your amp gauge shows, it might just have went bad on you.

[Wayfarer Malang]

Well the silver solenoid thingy has one black at the bottom no fuse like but a disconnect plug and with out it connected it will not run. battery is new and black wire at Alternator is 12 . omg I just forgot 12 point something.

also why dose this rv have two battery isolators? one by the batteries the other under the dash so I could not see the fuses I use a Fluke meter thingy and according to it it has no baring on the other so i guess it has to do with the trailer brakes  I took it out so I could see the fuses because with it in the way you have no access to them.

i al so have a switch on the dash that says bat con and the one next to it says flash I have no idea but if I run from  Black Alternator to Black solenoid would that work.. 

Also I was told that a rv should run if you disconnect the battery and that will tell you if the system is charging. True or false??? Also I am updating I did find a fuse that has nothing to do with charging and it blown all it says is 263 what is that? its screwed on to the side were batteries are.....

Thank you so much And yes I read and copy anything sent I love to learn.
Peace

[ClydesdaleKevin]

The second battery isolator is most likely an emergency start solenoid...there should be a momentary toggle switch somewhere on your dash...it allows the engine to be started off the coach batteries if your engine battery ever dies.  Its a very good thing to have.  Also, some rigs have even more solenoids kicking around.  We have a third that allows us to turn power off to the dash when parked...a feature we like after reading LJ-TJs horror stories about dash fires...lol!  Good luck and keep at it...you'll find the culprit.  And make sure every one of your grounds is clean and tight, as well as every other electrical connection.

Kev

[Elandan2]

There is also a splice in the wiring harness going from the alternator to the starter relay.  It is about the center of the engine on the right side.  The harness is located along the rocker cover next to the intake manifold.  You may want to check that as well.  The solenoid under the dash is probably for the heater fan motors.  Rick

[M & J]

Where is she? Arent there any members close enough to go give her a hand?

[ibdilbert01]

Only 12.(something) volts at the lug on the alternator where the black wire is "while" the engine is running assures us you are not charging.   

On the regulator center pen, you need to test for ~12v with the key on and let us know what you find.   Also make sure the voltage regulator body is grounded good.     


Also make sure your alternator belt is tight!

[DaveVA78Chieftain]

Well, Monday has come and gone.  Hope she was able to work it out.  - Dave

[Wayfarer Malang]

No I just can't find the problem. I just don't know un-tape wires. so I have a good starter battery and when that gets low use jumper cables to the deep cycles. I am still wondering what would happen if i ran a wire to the bid black wire and went to the solenoid the wire in it now if i unplug it the engine  stops. If i save money from my disability check this mount and the next i will take it to an rv shop. after two weeks of reading meters tracking wires I am done for now. since my alternator read 12 . something I am thinking of replacing it.
I went all the way from Iowa to Illinois on just batteries so I fuss blind faith will get you thru. I want to thank all of you for the help and if I find it I will post it, or if anyone has any more ideas I will keep reading the posts. I did find a blown I guess it called a fuse thats screwed to the wall of battery compartment and all it says on it is 628 now how do you know what amp to replace it with I ask you so the next time I am at a strs that sells them I will just guess.
Hugz Peace 

[DaveVA78Chieftain]

Look at my web site at http://dave78chieftain.zxq.net/
On the left side you will see selections for Charging System description and Troubleshooting.  Read through the information and let me know if you understand it.  You need to understand what is being done before doing it.  There also links to the Dodge MH wiring diagrams there.

Dave