help! broken down! Alternator Issues

Topic: help! broken down! Alternator Issues (Read 4751 times) previous topic - next topic

Re: help! broken down!

Reply #75 – May 11, 2016, 09:43:25 am

Quote from: Walkerfam7 – May 11, 2016, 09:14:42 am

We cleaned everything off yesterday between waves of monsoons hitting Cincinnati and started the coach up without the boost to find that our dash voltmeter as well as the trimetric were still only measuring the start batteries at around 12 to 12.5 :/ Anyways, Pete is going to come help us troubleshoot a bit today. We will see if someone more experienced with the coaches will notice something that we have missed.

FMCA here told us they have some local repair shops that will come out here to us. Would it be wise to have someone like that check it out if Pete can't help? Or would you guys choose to just bring the coach straight to Cummins?

If Peter brings a volt-ohm meter with him and knows how to use it then it should be pretty simple to see if the alternator has a reasonable output. If it's not easily diagnosed and your generator is operating and charging your batteries then it should be possible to drive to a repair facility. I would recommend that rather than paying for someone to come to you. Peter has previously mentioned Holman RV and they are located not too far from you and so that would be my recommendation. A Cummins shop may not necessarily be familiar with motorhome electrical systems.

If the alternator has failed then a quick Google search shows an alternator rebuilder not far away in Northern Kentucky. Auto Parts Rebuilder No. Kentucky & Cincinnati, OH 859-740-4064

The alternator is probably a Leece-Neville and so the following links may also be useful: Prestolite / Leece-Neville Distributor Search
Prestolite / Leece-Neville Alternators and Starter Motors

Re: help! broken down!

Reply #76 – May 11, 2016, 09:47:56 am

Sounds like an electrical issue-- so Cummins would not be my first choice. If you and Peter are not able to diagnose, get a repair guy familiar with coach/12 VDC wiring.

Absolutely first thing is to continue with what you are doing: verifying that all connections at battery, isolator and alternator are clean and tight. Pay particular attention to the small-gauge "sense" wire from isolator or chassis battery to alternator. Small and easy to break.

Then do the troubleshooting with Peter's help:

Shore power disconnected, generator off.

Check and record voltage at chassis battery bank and at house battery bank. 12.7= fully charged battery at rest. Anything above that is surface charge and you need to remove-- couple of lights on for a few minutes should do it). 12.2= 50% discharged battery at rest. This would indicate that your on-board charger is not working properly.

Start engine and bump to high idle (1000 RPM).

Recheck voltage at chassis battery bank and at house battery bank.

You can also do the above checks at the large lugs on the battery isolator, as you have large-gauge wires from each battery bank to the isolator. Only a loose or corroded wire or connection would give different readings between battery and that battery bank's lug on the isolator. Readings at each battery bank should now be 13.5 to 14.2 VDC. If so all is well.

If not, back to the isolator: Check voltage at the center lug (wires are numbered and your wiring diagram will tell you which wire comes from the alternator B+ terminal). Should be 14- 15 VDC (you lose about .7 VDC across the diodes in the isolator between the alternator "in" terminal and the two outer lugs to the two battery banks). If B+ is 14-15, but either battery bank's isolator lug is not reading about .7 VDC lower, the isolator is bad (likely a diode has failed).

You can also CAREFULLY check voltage at the back of the alternator. Probably easiest from inside with bed raised. With engine at 1000 RPM. Locate each of these with engine off, so you know what you are doing when the engine is running:

B+ to ground= 14-15 VDC.
Sense terminal to ground= chassis battery voltage (probably 13.5-14.2).
If you have an excitor/ignition terminal, it will chassis battery voltage when measured to ground.

If sense terminal and excitor/ignition terminal are reading chassis battery voltage, but B+ is not in the 14-15 VDC range, label the wires, tape (actually I use pieces of old bicycle inner tubes) to cover the ends, so no wire ends can touch ground. Remove alternator and take to alternator shop.

Check with your alternator manufacturer for the name of an authorized shop in your area-- that is your best bet.

Re: help! broken down!

Reply #77 – May 11, 2016, 09:48:05 am

Quote from: Walkerfam7 – May 11, 2016, 09:14:42 am

Would it be wise to have someone like that check it out if Pete can't help?

It's easy for all of us to "Go to the dark side" in troubleshooting, that's why a fresh mind is always welcome. + let us know what kind of cookies he brings!

Re: help! broken down!

Reply #78 – May 11, 2016, 02:17:43 pm

First off, Peter is awesome! We didn't quite figure out the root of the problem, but we are getting closer. We are going to take it into Cummins because he highly recommends it and has a personal relationship with them. Second, thanks for the cookies, Beth!!! Sorry Mike, we would share if you were close by

They are some tasty looking chocolate chip cookies!!!!

Re: help! broken down!

Reply #79 – May 11, 2016, 02:53:37 pm

Trent you might want to twist and wiggle the chassis battery cables. I had a starting problem that was a real pain. Turned out to be a defective positive cable that did not reveal the problem until I removed it. I could take a picture of it. Good luck..

Re: help! broken down!

Reply #80 – May 11, 2016, 03:08:47 pm

Following our two conversations, did you verify that you have 12+ VDC at both the ign and sense terminals of the alternator with engine running?

If not, the alternator may be fine and sitting there saying "sure, if you want power all you have to do is tell me" (via those two small wires).

Re: help! broken down!

Reply #81 – May 11, 2016, 03:30:05 pm

I had a similar problem after I had the alternator rebuilt and replaced the isolator. We were on the way to Colorado and after about 3 hrs I noticed the voltage going south. Ran on generator to our destination. I finally ran it down to a self resetting circuit breaker that was stuck in the open position. The circuit breaker was mounted on the firewall left of the isolator. (as you're looking at it from under the bed) I went to a grocery store in South Fork and found one for $3.99. Solved my problem, went from 0 to 14.5 V

I don't have the coach here but I believe it was a 15amp.

Re: help! broken down!

Reply #82 – May 11, 2016, 03:59:23 pm

Thanx to Brett who is such a great guy to put up with the calls and getting us throught the details of the troubleshoot. Trent & Siobhan are wonderfull and have a full slate of 5 boys to contend with. But honestly I never knew they were around. Great job bringing up the gang of boys. Surely there will be lots more fun stuff down the road than putting up with coach issues.

JOR's coach (now Trent & Siobhan's) is trully one of the most elegant 1995 U300's around...the envy of the campground.

In summary:

Start batteries are okay but are 8 year old Optima Red Tops (3) with 12.6 to 12.7 VDC steady state. May need to replace these sooner rather than later.
The dash showed good alternator voltage although I could not get clear readings at the alternator lugs. Thnx Brett for the education of these 4 pole alternators.
Boost circuit tested out just fine as did the converter/charger.
House battery banks were in good state of charge with good terminal contact. 12.8VDC steady state. 13.8 with charger

M11 fires up beautifully with just coach batteries which were charged with boost circuit overnight.

It appears the alternator may be in need of attention due to the low volt condition encountered on the road. I suggested to Trent that Cummins Bridgeway which replaced my alternator a few years back may diagnose the alternator more thoroughly. Mine is a Leece Neville, Trent's coach has a Herr Branded unit.

Called Cummins and they agreed to look at the unit this afternoon and go from there.

I really wish I was more mechanically inclined with this kinda stuff, but with Brett's assistance on the phone in a noisy engine compartment area we did the best we could. Many thanks again, Brett.

Re: help! broken down!

Reply #83 – May 11, 2016, 04:29:45 pm

If voltage readings are not what I posted above, and alternator is a Hehr, here is the U.S. distributor (Ft Worth, TX). BUT, the cleaning and tightening of all connections may have fixed it. Said another way, a loose or corroded connection can be fixed. But doubt a bad alternator will suddenly start "acting right".

HDPSI POWERLINE Alternators

Troubleshooting guides: Untitled Document

And, they could certainly tell you who their authorized dealer is in your area.

HD Power Solutions Inc Contact Information

4616 Fairlane Avenue
Fort Worth, TX 76119
Phone: 817-535-0284
Fax: 817-531-2755
Email: sales@hdpsi.co

If Peter says Cummins has a guy savvy on 4 connector RV alternators with isolators, go for it. If not THAT is who you are looking for.

Re: help! broken down!

Reply #84 – May 11, 2016, 06:12:11 pm

Last year my mechanic determined the bearings were going out on both my alternator and A/C compressor. He sent them out to be rebuilt and they have worked flawlessly since. the price was very reasonable. I'm in the Los Angeles area, and I can ask where he sent them if anyone needs to know. This is better than having a rebuilt alternator installed and then finding it is not the right model.

Re: help! broken down!

Reply #85 – May 11, 2016, 06:28:40 pm

Tom,

I agree-- in fact at 100k miles, I pull the alternator and have it overhauled by a dealer recommended by the alternator manufacturer.

New bearings and brushes= piece of mind.

Remember, alternators are in a MUCH hotter location on a DP than in the front of a front engine truck AND air flow is backwards.

Re: help! broken down!

Reply #86 – May 11, 2016, 09:26:05 pm

Can I suggest that this thread title be changed to "Alternator Problem" to aid in future searches? There is a lot of good alternator info in here.

Re: help! broken down!

Reply #87 – May 11, 2016, 10:39:14 pm

Ok...so here's where we are at with the Cummins service center...they said they *think* its the alternator and are trying to locate a replacement. We are a bit uncomfortable with the *think* part of this because if its not the alternator, then we have spent a whole lot of money that we really can't afford to spend for no reason. We would much rather go a more inexpensive route of having it rebuilt or something. If that is an option, our next problem would be the 7 hour drive from here back to Michigan. Would it be reasonable to drive all the way back there running the generator and the boost the whole way? Then once we get back we would have to pull the alternator and ship it out somewhere which leaves us immobile for how long? We usually stay at a church we are working for and run every 5 days or so over to Camping World to dump, but we wouldn't be able to get there without an alternator, which leaves us staying at a campground. The last campground that we stayed at in the area cost us $1000 for the month. :/ I know owning a motorhome isn't always a budget friendly way of living, but we try to keep costs as low as possible.

Re: help! broken down!

Reply #88 – May 11, 2016, 10:46:29 pm

I believe you can run indefinitely with no alternator so long as the generator and charger are keeping the batteries charged and the boost switch is on. Just remember to turn off the boost switch when stopped so a tripped breaker won't result in all batteries going dead at the same time.

A good mechanic should know where to send the alternator to be rebuilt, but I would go for a second opinion before doing that. It might still be a simple wiring issue.

Re: help! broken down!

Reply #89 – May 11, 2016, 10:50:19 pm

Ok, running home on boost with generator running will be fine. Same with short trips to CW on genny and boost. Should be able to diagnose Alternator failure vs. "I think"

Re: help! broken down!

Reply #90 – May 11, 2016, 10:57:29 pm

Quote from: Tim Fiedler – May 11, 2016, 10:50:19 pm

Ok, running home on boost with generator running will be fine. Same with short trips to CW on genny and boost. Should be able to diagnose Alternator failure vs. "I think"

if you do run to CW for dumping with alternator removed, make sure the wires are well taped and securely out of the way of any potential moving parts/vibrations.

Re: help! broken down!

Reply #91 – May 12, 2016, 08:44:01 am

When our alternator failed on the way back from Texas I found that the cruise would cut out when the voltage of the batteries dropped to about 10.5V. I would then start the generator and run it until voltage read around 13V, then shut it off until voltage dropped again. Repeated the cycle quite a few times but made it home. Used the cruise "dropout" to monitor the batteries.
We drove almost 450 miles this way, but tried to and succeeded in not driving at night, as headlight usage created too much of a drain too quickly.

Re: help! broken down!

Reply #92 – May 12, 2016, 08:51:51 am

Again, you need a shop that is familiar with 4 wire RV alternators with diode based isolators. Ain't rocket science, but COMPLETELY different than OTR trucks.

From the two calls I got from the tech at Cummins, he was not familiar with this system and I am not sure he read the troubleshooting guide in my link above. Have they run through the tests I posted above. Should be no guessing on this.

And, call your alternator manufacturer in Ft Worth (I posted info above) for their recommendation of a rebuild shop in your area. No need for a new one unless the rebuild shops declares it beyond repair.

And, as long as the bearings in the alternator are OK, leave all the wires connected, generator running and boost on. For as long as you like.

Re: help! broken down!

Reply #93 – May 12, 2016, 08:59:17 am

Yes, Brett. This is the exact conclusion we have come to. We are going to pay the nearly $300 bill ($135/hr) to drive away...lol. We are waiting on HDPSI to open. We have been calling already, but they aren't open yet and I can't find any hours posted anywhere, so we will just keep calling until we get someone.
From the phone calls you had with them, did it seem that it WAS, in fact, the alternator that was malfunctioning or could it still be a possibility that it is a sensor connection that isn't functioning properly?

Re: help! broken down!

Reply #94 – May 12, 2016, 09:02:43 am

I think what was confusing the techs here is that we have a different alternator than what is found in the wiring diagrams that we have. I'm not sure if the original was replaced, or if, like the engine itself, it had a slightly unique alternator than what was supposed to be standard on this coach. Maybe it has to do with the horsepower upgrade that was done on the engine? I have no idea....

Re: help! broken down!

Reply #95 – May 12, 2016, 09:37:08 am

Quote from: Walkerfam7 – May 12, 2016, 08:59:17 am

Yes, Brett. This is the exact conclusion we have come to. We are going to pay the nearly $300 bill ($135/hr) to drive away...lol.

Based on my recent Alternator experience, my alternator is also a Hehr Powerline, you will get great technical help. Ask for Rodney. Hehr sold their alternator group about 7 years ago. It is now just Powerline and the number I called is 817-535-0284.

Remember, the difference in cost of replacing my alternator vs repairing it was well over $1000.

Now knowing you also have a Hehr Powerline, your problem may be the same as I had. If the brush channels are just dirty the brush could have lost contact with the rotor and through your tinkering they may now be working. You might be able to drive for many more miles before the alternator acts up again. That doesn't mean you should ignore the event but you can put off repair until you get to a competent repair shop. A good one in Oklahoma is Big Cabin Diesel repair on I-44 in North Eastern, OK. There is also a campground there. I doubt that you will have bearing problems. The repair shop said the bearings in my Powerline were the best bearings on the market and showed no wear whatsoever. The biggest problem you may find is finding an alternator repair shop. Even Powerline has very few dealers and did not have a usable referral in our part of Oklahoma. If you will travel back home through OK, Pryor Auto Electric, in Pryor Oklahoma is the shop that fixed mine and is now familiar with our Powerline Alternator. They aren't fast but they are very cheap, $30 for cleaning my alternator.

Re: help! broken down!

Reply #96 – May 12, 2016, 11:24:02 am

Quote from: Walkerfam7 – May 11, 2016, 10:39:14 pm

The last campground that we stayed at in the area cost us $1000 for the month. :/ I know owning a motorhome isn't always a budget friendly way of living, but we try to keep costs as low as possible.

A Coach Buck a month? Wow, must have been a very plush campground!

Let us know what's happening, all the best, M

Re: help! broken down!

Reply #97 – May 12, 2016, 11:45:41 am

It was a KOA...not exactly what I would call plush, but it was literally the only campground in the area that wasn't closed for the winter. :/

Re: help! broken down!

Reply #98 – May 12, 2016, 12:46:32 pm

So....here's where we landed today...

I'm attaching a picture of the report from Cummins. If they tested the wiring correctly it sounds like it is the alternator that is having issues. But....we don't want to replace. Its a good alternator that can be serviced and we would rather have the same alternator back in the rig. So, we called Powerline. The only local place that deals with repair of Powerline alternators no longer has a service center. They would repair the alternator there, but we would have to remove it and bring it to them. Don't really have the tools to be doing that here.

So, we are going to drive back to MI on generator and boost and remove the alternator once we are settled up there, probably Monday, and send it in to Powerline in Texas and have them repair it for $95 plus parts. Hopefully that will solve our issues.

Thanks to all who have helped us try to solve the mystery. Don't know where we would be without you. Probably on the side of the road broken down still...
Hopefully we will get to pay the help forward someday when we have had many years experience!

Re: help! broken down!

Reply #99 – May 12, 2016, 12:54:39 pm

Yup, if voltage on sense wire (should be same as chassis battery voltage) AND, repeat AND 12+ VDC on IGN terminal, with engine running then indeed pull the alternator and have it rebuilt.

When your tech last called me, he had not traces the IGN wire/verified voltage. Assume this was done before alternator declared DOA.

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