Charging issues

Topic: Charging issues (Read 2427 times) previous topic - next topic

Re: Charging issues

Reply #75 – March 12, 2023, 06:34:59 pm

Well I cleaned wires and tightened a few things up.
Disconnected the ignition wire from the alternator and got 11.8 volts with the ignition on.
When I reconnect it and put the tester on it (with an aligater clip), I have nothing!

Ran pigtail from the Isolator chassis side to the other post (Sence wire) and still only had basically nothing for volts at the center lug.

All of a sudden the idler bearing squeak got so bad I could not hear my cussing.
So I'm gonna replace that now and probably put on a new belt for good measure.
Have the breaker ordered that's stuck open and idler ordered.
Will work on it again when I get that fixed.
Belt shouldn't be too hard to find.

Re: Charging issues

Reply #76 – March 12, 2023, 10:39:25 pm

Quote from: Wpduffey – March 12, 2023, 06:34:59 pm

Disconnected the ignition wire from the alternator and got 11.8 volts with the ignition on.
When I reconnect it and put the tester on it (with an alligator clip), I have nothing!

So I'm gonna probably put on a new belt for good measure. Belt shouldn't be too hard to find.

Your weird voltage readings may be due to a problem with your multimeter, or a problem with your test leads (alligator clip).

Try to always use a Gates Green Stripe belt if possible. They are the best quality.

https://assets.gates.com/content/dam/products/gates/power-transmission/micro-v-belts/automotive/heavy-duty/heavy-duty-sell-sheet-fleetrunner-belts.pdf

Re: Charging issues

Reply #77 – March 12, 2023, 11:00:58 pm

Not arguing with you what so ever just trying to figure it out too.
I have good voltage with the same alligator clip with the ign wire disconnected and ignition on!
Not sure why i would have nothing, same clip, same wire and same meter with the wire attached.
Meter shows 13.4 volts at each battery every time.
Meter works fine. Wire and clips are fine. Alternator not working worth a dern.
And i did order a green line belt. ty

And believe it or not my coach is in very good condition, wiring isnt butchered or chopped up, very little rust, Just have something weird going on. But i do appreciate your assistance.
Thank you,

Re: Charging issues

Reply #78 – March 12, 2023, 11:09:48 pm

Quote from: Wpduffey – March 12, 2023, 11:00:58 pm

I have good voltage with the same alligator clip with the ign wire disconnected and ignition on!
Not sure why i would have nothing, same clip, same wire and same meter with the wire attached.
Meter works fine. Wire and clips are fine. Alternator not working worth a dern.

I can think of no logical explanation for the test results you are reporting.
You have not yet mentioned the make and model of your new alternator. Is it a Leece Neville? If so, what model number?

Re: Charging issues

Reply #79 – March 12, 2023, 11:21:41 pm

Think your coach sat near water and moisture in it's home state,those screws on the metal panel holding the solenoid look
mighty rusty,make sure none of the components are grounded thru that metal plate,if so that may be a problem,you also have
that old insulation falling apart on the compartment walls,most of us with the older coaches have redone that,when you get a
chance come look at mine.

Re: Charging issues

Reply #80 – March 13, 2023, 12:02:10 am

Yes sir it is a new leese neville 2824LC i believe. The one one of the guys here sent me then links to. It didnt have the original one on the coach when i bought it.

And yes i know the insulation needs to be replaced. Its the original. I am actually looking at using roxul on it and the generator compartment, But i have only owned it three weeks..and it came from atlanta by way or florida around 15 years ago. There is very little rust under the bus. Those plates are actually about the worst i have seen anywhere so far.

Re: Charging issues

Reply #81 – March 13, 2023, 07:47:53 am

Quote from: Wpduffey – March 12, 2023, 06:34:59 pm

Well I cleaned wires and tightened a few things up.
Disconnected the ignition wire from the alternator and got 11.8 volts with the ignition on.
When I reconnect it and put the tester on it (with an alligater clip), I have nothing!

One thing at a time, sir, one thing at a time.

"What we have here, is a failure to communicate."
Well, you've been bitten by the High Impedance trap.

With the wire disconnected you measured leakage voltage on the wire. When you reconnected the wire, the electrons for that leakage voltage were bled to ground through the exciting circuit. Your wire is "patent" but somewhere along the way, between source and load, there is a very high resistance connection.

Remember: Voltage is electrical pressure, so electron need move, only push.
Current is the flow of electrons, each screaming "I'm Freeeeeee!"

It used to be that the cheap Radio Shack multi meter put enough of a load on the circuit being tested that this trap didn't really exist. But even the $8 Harbor Freight multi-meter has a high impedance input and can measure voltage without causing any electrons to flow.

Re: Charging issues

Reply #82 – March 13, 2023, 09:09:43 am

Quote from: Wpduffey – March 13, 2023, 12:02:10 am

Yes sir it is a new leese neville 2824LC i believe.

OK, that is the correct type/size alternator for your coach. I just asked because I'm trying to eliminate all possible reasons why this setup is not working. You have the right alternator. You have hooked up new EXCITE and SENSE wires, and you get the correct voltage readings (SENSE hot all the time, EXCITE hot only with ignition switch ON) from both wires when the wires are not connected to the alternator.

But then you connect the wires and get no alternator voltage output with engine running. This is (to me) very puzzling.

Old Toolmaker has offered a somewhat esoteric explanation... Go back and check the integrity of your new wiring - make sure everything is tight and secure.

PS: Don't worry about your engine compartment insulation. My engine compartment has looked worse than yours for the 10 years we've owned our coach. It's on my list of things to do, but never makes it to the top. And yet I sleep just fine at night.

Re: Charging issues

Reply #83 – March 13, 2023, 10:54:33 am

I have parts ordered to fix a couple other things that are in the way of finishing this.
1) a new tensioner and belt. (The bearing started roaring on me mid alternator)
I ordered a new tensioner and a set of bearings for the old one (to rebuild as an extra)
2) That one breaker on the left against the forward firewall is stuck OPEN! and all those contacts are crusty. I ordered new breakers and relays to replace all that. Then I will re-address this issue and give yall feedback.
Thanks so much,

Re: Charging issues

Reply #84 – March 13, 2023, 12:26:40 pm

Quote from: Chuck & Jeannie – March 13, 2023, 09:09:43 am

Old Toolmaker has offered a somewhat esoteric explanation...

The only word that I expected to be looked up in any good dictionary was "patent" and that I borrowed for its medical definition.

Re: Charging issues

Reply #85 – March 13, 2023, 01:16:04 pm

Old T,

No offense intended. It's not yer words...it's the electrical theory. Sometimes I have to think about technical stuff for a while until the fog clears...

So I connect one end of a wire to a known good voltage source (say 12 volts for example).
Then I check the other (unconnected) end of the wire with a multimeter and read the same voltage (12 volts).
Then I connect the (unconnected) end of the wire to a terminal on some electrical device (that is not turned on or operating).
Now, when I check the voltage on the end of the wire that I just connected, I find no (or very low) voltage.

You offer as an explanation: "...somewhere along the way, between source and load, there is a very high resistance connection".

I'm trying to imagine what would constitute a "very high resistance connection". Over the years, I've wired up probably hundreds of 12 volt electrical devices in various vehicles. Due to necessity, haste, or frugality, I've sometimes used junky old lengths of wire cobbled together with multiple amateur crimped connectors and twisted together splices covered with cheap electrical tape. In spite of that, the devices have (almost) always powered up and worked...at least for a limited time.

In the case of Wpduffey and his recalcitrant alternator, I am assuming that his newly installed EXCITE wire is just a single length of wire with some sort of connector on each end. IF this assumption is correct, I have a hard time understanding how your explanation would apply. But as I've said around here many times, I'm just an English major so electrical theory appears, to me, to be equal parts magic and science.

Re: Charging issues

Reply #86 – March 13, 2023, 07:23:03 pm

Quote from: Chuck & Jeannie – March 13, 2023, 01:16:04 pm

Old T,

No offense intended.

In the case of Wpduffey and his recalcitrant alternator, I am assuming that his newly installed EXCITE wire is just a single length of wire with some sort of connector on each end. IF this assumption is correct, I have a hard time understanding how your explanation would apply. But as I've said around here many times, I'm just an English major so electrical theory appears, to me, to be equal parts magic and science.

First of all I'm thinking of a resistance on the MegaOhms scale.

You wrote "I am assuming that his newly installed EXCITE wire is just a single length of wire with some sort of connector on each end."

And I answer: With a self resetting circuit breaker in between whose contacts may have grown resistive over the years.

Second a corroded connection easily fits the bill, although in the past some pencil "lead" on a piece of paper has worked well as a megaohm resister for a grid leak. That's the charge that builds on on the grid of a vacuum tube unless given some place to go.

Dirt on an open connection is enough to pass enough electrons to fool a modern high impedance voltmeter.* I myself got bit last summer and threw myself on my soldering iron, confessed my transgression, and accepted the abuse directed my way after wasting a day chasing electrical færies.

*Touching the probe with a finger tip is enough to drain off the leakage voltage. Most of the time.

Re: Charging issues

Reply #87 – March 13, 2023, 08:43:35 pm

Guys i cant really do anything with lt right now until i get my parts in but i do appreciate yall thinking about it. Let me state a couple clear facts here to make sure we are reading the same music.

1) i have a brand new leece neville 2824 alternator (hooked up correctly and grounded well)
2) the E6 ignion wire from the ignition is hot when on (13+ volts) when tested loose. When i bolt said wire to alternator and test it, i have no voltage.
Oh and i did check it at the breaker by the front door as well. A good solid 13+ volts with ley on and zero when off.
3) existing since wire E59-E86 was not hot at the alternator when connected. I did find an open breaker that i showed a picture of earlier. I have an assortment of them ordered and will clean all that up. I did run a good solid hot wire (with good copper strong alligator clips) from the alternator to the chassis hot terminal on the isolator as brett suggested to try and test the alternator. Along with the already ignition hot wire hooked up on the alternator. Zero voltage at the center terminal on isolator when running.
4) i was mistaken earlier on when i said i had a 2-3 volts at the middle isolator terminal and the alternator when running. It was slowing millivolts and it was dark and rainy. I actually have nothing there. Running or dead.
5) both batteries show a solid 12.67 volts.
6) both outside isolator terminals show 12-13 volts. (Which they should be same as batteries)
7) dash guage was reading about 11 volts. Testing the wires on the back with meter 11.97 volts

Any other specific questions please ask them. Thanks

Re: Charging issues

Reply #88 – March 13, 2023, 08:55:52 pm

Please update us after replacing the parts mentioned.

Thanks.

Re: Charging issues

Reply #89 – March 13, 2023, 09:09:19 pm

I absolutely will follow up. And im learning a lot along the way. Its a PITA way to learn but knowledge is knowledge!

Re: Charging issues

Reply #90 – March 13, 2023, 09:15:49 pm

I made up a test light using a halogen headlight bulb as I have had good readings with a voltmeter
and an ordinary test light but wire wouldn't carry any current. Also just because the alternator is new
doesn't mean it works

Re: Charging issues

Reply #91 – March 13, 2023, 09:49:46 pm

Old T. is correct, if this wire had 12v measured when disconnected at the Alternator end and zero volts when connected, there would have to be a very high resistance either in series, or at its source, or there would be a tripped breaker, blown fuse or the smoke would be released from somewhere. Or.... the wire would become a heating element!

While disconnected, try using a 12v test lamp instead of a meter.

Re: Charging issues

Reply #92 – March 20, 2023, 06:28:59 pm

Just to give yall a quick update got all my parts.
2 of the belts were incorrect off that parts list.
So it's gonna be a minute before I put it back together.
Look like 97 and 98 were the same belts but the ac and alt are definitely short. Looks like I'm gonna need that 63.5"belt.
Thanks,

Re: Charging issues

Reply #93 – March 22, 2023, 08:30:05 pm

Good evening FT fans and mechanics.
First and foremost thanks for all your help.
Have correct alternator and a full new set of belts and idler/tensioners
I now have 12.99 volts at the middle terminal on the isolator.
Here is what I found.
The 15 amp breaker under the bed is the one that most coaches have in the chassis batter compartment was stuck open. (NO SENCE WIRE) rebuilt that board and replaced both breakers and relays, cleaned everything up (boom voltage)
The E6 wire (ignition hot) has voltage until you hook it to the alternator. No idea why or what to do with it now.
I ran a temp ignition hot (as wolf suggested) from the remote start switch (boom voltage)

So long story short the coach had no sense or ignition excite voltage (so it can happen) not sure how long its been that way, I do know that it's had 6 alternators including this one.

YeeHaw!

Now any recommendations what to do with the E6 wire and where do yall recommend I run another permanent ignition wire from?

I have 2" roxul board on the way to finish cleaning up the engine compartment. Also gonna order a couple nice led under hood lamps. I'd appreciate if yall have an opinion there too.

Quick parts update I wound up using at k080638 alternator belt and a 9470 ac compressor belt. Which it doesn't show for a 1998 U270.

Re: Charging issues

Reply #94 – March 22, 2023, 09:22:21 pm

Quote from: Wpduffey – March 22, 2023, 08:30:05 pm

I now have 12.99 volts at the middle terminal on the isolator.

Hate to rain on your parade...but 12.99 volts at the center post on the isolator is still not adequate. Conventional wisdom says you will lose approximately 0.7 volts across the diodes in the the isolator, which means the battery banks will only see about 12.3 volts. This will not charge your batteries. You want to see 14+ volts on the isolator battery posts, which means you need at least 14.8V on the center post.

More investigation is needed.

If it was me, I would run a sense wire direct from the positive post on a start battery to the alternator. Check if the voltage at the isolator center post improves.

See the post linked below, written by Don (one of the Kool Kids on the Forum). Tells you what voltage AGM battery needs to see for proper charging.

AGM Battery Homework

Re: Charging issues

Reply #95 – March 22, 2023, 10:05:10 pm

Oh i know im not done but At least im charging now, we had nothing before. That in itself is a small victory.

What about the excite wire? Where should i run that from. And what to do with the E6 wire? Tape it up?
Its dang sure easy enough to run another wire frim the battery.

Batteries are old too, could this have any effect here. Im gonna replace them. I just wanted to get it charging.

Re: Charging issues

Reply #96 – March 22, 2023, 10:13:21 pm

Quote from: Wpduffey – March 22, 2023, 10:05:10 pm

1. What about the excite wire? Where should i run that from.
2. And what to do with the E6 wire? Tape it up?
3. Batteries are old too, could this have any effect here.

1. Your excite wire is fine for now. It seems to be working.
2. Tape it up, or put a crimp butt connector on it. You just want to be sure it can't cause a short circuit.
3. The batteries being old is not a factor. You still need to achieve proper charging voltage at the isolator center post.

Re: Charging issues

Reply #97 – March 22, 2023, 10:37:28 pm

FYI: that temp excite wire is just a jumper from the remote start to the post via alligator clip. I kust taped of the original to make sure it didnt short out. The since wire was dead because of that breaker being stuck open. Had nothing on it.

Re: Charging issues

Reply #98 – March 22, 2023, 10:53:46 pm

Connecting the EXCITE wire at the remote start switch is as good a place as any. Run a permanent wire that is protected as much as possible from chafing and heat. Tie it down with wire clips to keep it from moving around when you are driving down the road.

I like to use the black plastic split wire protector on every wire I run in our coach. It won't stand up to super high temps, so you have to watch where you run it in the engine compartment. But otherwise it does a good job protecting the wiring.

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As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Charging issues

Reply #99 – March 23, 2023, 07:45:55 am

Quote from: Wpduffey – March 22, 2023, 10:05:10 pm

Oh i know im not done but At least im charging now, we had nothing before. That in itself is a small victory.

What about the excite wire? Where should i run that from. And what to do with the E6 wire? Tape it up?
Its dang sure easy enough to run another wire from the battery.

Batteries are old too, could this have any effect here. Im gonna replace them. I just wanted to get it charging.

The E6 Excite wire needs to be a switched wire (voltage only with ignition on). The old E6 wire needs tape over the end for now.

The voltage sense wire from the alternator needs to go "at least" to the start battery output terminal on the battery isolator. As Chuck wrote, best practice is to run a small wire from the positive terminal on the battery to the sense terminal on the alternator so that the voltage sensing circuit can allow for all line losses and allow the alternator to provide the correct voltage at the battery.

Your "old" batteries would only be a problem if they are "leaky." If you can disconnect your batteries and they measure the same voltage or higher after 24 hours, those batteries aren't a problem in this case.

Sometimes, running a temporary wire or two just to prove that your expensive new alternator really does work is a big step forward if only for peace of mind.

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