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Topic: Charging issues (Read 2784 times) previous topic - next topic

Re: Charging issues

Reply #40 –
Quote from: Wpduffey –
OK I have nothing at either of the small terminals with the ignition on.
That wire is marked E6 that goes to ignition on the alternator

Temporarily disconnect them at the alternator and isolate so they can't touch ground.

Run new temporary wires as discussed in my post above.

Again, not that difficult to either trace or remove and replace the sense and excite wires.

Re: Charging issues

Reply #41 –
This is the only solenoid or anything other than the isolator in that area

Re: Charging issues

Reply #42 –
Trace that wire, must be broken somewhere. It will not charge without ignition power on it, and you must have constant battery voltage on the sense wire or else the alternator won't know how much to charge.

Re: Charging issues

Reply #43 –
Well i will work that direction. Not gonna happen tonight. Hopefully this rain will stop for a while.
Thanks

Re: Charging issues

Reply #44 –
Well i will work that direction. Not gonna happen tonight. Hopefully this rain will stop for a while.
Thanks

Re: Charging issues

Reply #45 –
Quote from: Wpduffey –
Well i will work that direction. Not gonna happen tonight. Hopefully this rain will stop for a while.
Thanks
Rain I can understand.  Tomorrow is supposed to be a nice day, Sunday Rain.

Your alternator.  The small wires.  "I" or ignition is the excitation voltage and strangely enough travels from the ignition switch, through the idiot light on the dashboard to that terminal on the alternator.  Your problem could be as simple as a burnt out light bulb.

The other wire aka the sense wire: for all practical purposes is the positive test lead for a high impedance volt meter.  That's it.  that's all. It's whole raison d'etre is to allow for losses between the source and the load, the alternator and the battery.  The alternator's voltage regulator measures the voltage at the load using that wire and adjusts the alternator output voltage accordingly.

I agree with Brett: make a wire with alligator clips and go right to the battery just to prove out the new alternator.  The sense wire can remain connected but the "I" or "E" wire will drain the battery if left connected.

Re: Charging issues

Reply #46 –
Quote from: Wpduffey –
This is the only solenoid or anything other than the isolator in that area
I believe that is the BOOST solenoid.  It is not a solenoid brand that I recognize, but does look to be continuous duty rated.  I flipped your photo over so we can read the white label on one of the big red battery cables.  Cable ID number is B14, which matches ID number on the cables running from isolator to solenoid in the wiring diagram I posted in Reply #8.  Note that there are two big battery cables attached to each of the large posts on the boost solenoid.  The clean(er) red cables go from the solenoid to the battery isolator.  The dirty cables go from the solenoid to the respective battery banks.
See the diagram below (with some details added in red).

Re: Charging issues

Reply #47 –
Before the rain started again this morning. I started tracing wires and studying diagrams. I have 6am ignition excite fuse or relay in the main 12 compartment right beside the door.
#35 on the schematic. No continuity! I believe is the term. So its blown! I am not familiar with this type of set up.
Are they fuses?
Do you just replace them?
Do i need to order myself an assortment?
Do i have to disconnect this whole bar to get that one out? Looks like a lot of work to just change a fuse.
How does this work?

Re: Charging issues

Reply #48 –
The items you are looking at on that panel are circuit breakers, not fuses.  They should all be Type 1 "auto resetting" circuit breakers.  A auto resetting breaker will open if there is a short or excessive current flow in the circuit, but it should reset (close) as soon as power is removed from the circuit.  If the circuit breaker is "open" (shows no continuity between the posts) when there is no power on the circuit, then it may have failed.  In that case you would need to replace it.  See link below for more info:

Bussman Automotive Circuit Breakers - Wiring Products

Re: Charging issues

Reply #49 –
I was wrong, it has continuity when the key is on. Just keep thinking it has to be a blown fuse or something, i cant find anything loose worn or tattered in the electrical work. Cant image both of these being dead. I will definitely try new wires to see if it will turn the alternator on but i want to find out where its broken or loose

Re: Charging issues

Reply #50 –
Having a tone tracer will make it easier to trace the wires. Could the old alternator been OK and the
problem was no ignition current and no voltage to the sense post.

Re: Charging issues

Reply #51 –
The old alternator was not a duvac. Just a regular 160 amp.

Re: Charging issues

Reply #52 –
If your coach still has the diode-based battery isolator, you MUST use a DUVAC as that external sense wire signals the alternator to put out enough volts to compensate for the voltage loss across the isolator.  The goal is to get the correct charge voltage to the chassis battery (which also gets the correct charge voltage to the house batteries assuming the system is working properly.

Re: Charging issues

Reply #53 –
As Peter suggests, a tone tracer would be handy for checking the wires.  You can buy one for not much $ at the big box stores.  Since your coach has had so many alternator swaps, almost any kind of damage to the OEM wires is conceivable.  Perhaps the wires you have connected to your alternator are not connected to anything on the other end.  Stranger things have happened...

I wouldn't be too resistant to the idea of running a new set of EXCITE and SENSE wires.  It might be the quickest solution.

Re: Charging issues

Reply #54 –
Quote from: Chuck & Jeannie –
I wouldn't be too resistant to the idea of running a new set of EXCITE and SENSE wires.  It might be the quickest solution.

YUP!

Yes, long term, find the other end of both excite and sense, since both are HOT (sense hot all the time, excite ignition hot).

Re: Charging issues

Reply #55 –
So many comments to try and sort through on here. Im working offy phone. So let me clarify.
Excite wire needs to be hot with ignition on only
Sense wire should be hot all the time?


Sense is E86 and goes to the remote stop button after the cir breaker on isolator panel (there is not one there that i can see)
Excite wire is E6 and goes to circ beaker 35 in the main panel. (It has got to be broke somewhere in between.

Re: Charging issues

Reply #56 –
You can do what Chuck suggested and run two new  wires and get it going and then you have
lots of time to trace out the old wires and use them later if you want to. Yes to your last question.

Re: Charging issues

Reply #57 –
Yes that is correct

Re: Charging issues

Reply #58 –
Quote from: Wpduffey –
Sense is E86 and goes to the remote stop button after the cir breaker on isolator panel (there is not one there that i can see)
Looking at the bottom center portion of schematic B-2126 linked below, I would disagree with this statement.  According to the schematic, the SENSE wire is E59 (white) and it goes from the alternator to a 15A circuit breaker on the isolator panel, after which it goes to the START battery post on the isolator.  This same E59 wire is also shown in the small schematic I posted in Reply #46.
 
https://www.foreforums.com/index.php?action=media;sa=media;in=3297

Re: Charging issues

Reply #59 –
I dont have a circuit breaker in the isolator panel. Where is it and what does it look like? There is nothing there but the isolator, the solenoid and the batteries there. I saw all the pix in rhe other alternator posts. My doesn't look like that.