Alternator Failure (I Think)

[mre]

I could write pages, but this is the short of it.

Yesterday driving to Tok, Ak. I noticed the voltage starting to drop. It reached 12.0 +/-. I tightened the battery terminals and there was no change. I started the generator and the chassis batteries started to charge. Made it to Tok.

Made a call to Freightliner Costumer Service and said it was alternator failure. Contacted Fairbanks Freightliner and they agreed with the diagnosis. I have appointment Monday 7/29 where they were going to install a new altenator.

I left this morning with the generator running, however it would not charge the chassis batteries while the engine running as it did the day before not would charge them with the engine not running. Any guesses why?

I returned to the campground. It was a long morning with the repair shop across the street (by that I mean dealing with people who don't do well at focusing on the issue). They do not give much confidence, but I am letting them do the repair. The campground owner told my wife they are very good.

I managed, not the shop, to get a altenator delivered he tomorrow around noon through Freightliner in Fairbanks much to their dismay. I, of course hope all goes well with the repair, but I worry that with ever changing technology, private shop may not be current. Any thoughts on my technology concerns?

I'd did speak with Freightliner Fairbanks and they agreed to keep my Monday appointment check the coach out assuming, of course I make.

[tom chelbana]

All coach owners should have a voltage meter to find out what is working and what isn't working. Start by checking battery cables first. It's not usual for factory gauges to give wrong reading. Should be charging around 13.5 volts when the engine is running.
Newmar Man

[Sbrownstein]

I agree that it sounds like a cable and not the alternator. I had a lug crack going down the road at 55 MPH and the engine shut down, hit the boost switch and it started up again. Started the genny and drove for another 4 hours. Of course it wouldn't charge the chassis but it ran the engine. In your case I would take a really close look at the cables and the chassis battery ground connections as well as the engine ground strap since the alternator needs it to charge.

If it starts and runs you have enough current to do that however.

[mre]

Originally Posted by tom chelbana

All coach owners should have a voltage meter to find out what is working and what isn't working. Start by checking battery cables first. It's not usual for factory gauges to give wrong reading. Should be charging around 13.5 volts when the engine is running.
Newmar Man

The reading I got came after market gauge package plugged into the OBD (or the desiel equivalent) and not the dash. If I had to rely on the dash gauge, I would have never seen it -- my hands and steering wheel block most of the gauges.

I did check the voltage as did the shop but not at the time the incident occurred. I wish I had.

Thanks.

[twinboat]

How long did you have the generator running before you returned to the CG ?

I don't know what Tok is, but if you were dry camping, your battery isolation/combining system will not allow your inverter/charger ( running off the generator ) to combine the battery banks, so the chassis batteries will charge, until the house battery bank was charged up to about 75% to 80% or 13.6 volts.

Depending on the house battery voltage at startup, even if the house bank was charged on shore power, there could be a 10 minute delay thru the isolation system.

[mre]

Originally Posted by Sbrownstein

I agree that it sounds like a cable and not the alternator. I had a lug crack going down the road at 55 MPH and the engine shut down, hit the boost switch and it started up again. Started the genny and drove for another 4 hours. Of course it wouldn't charge the chassis but it ran the engine. In your case I would take a really close look at the cables and the chassis battery ground connections as well as the engine ground strap since the alternator needs it to charge.

That's interesting that it would run the engine while not charging the batteries. When I started out this morning the voltage immediately started to drop then DIC showed low voltage along with dinging. The DIC showed:. (We internet and the image would not upload.

! AUTO IDLE
SYS VOLTAGE 12.0V
THRESHOLD 13.4V

This was at high idle. I

["007"]

Your battery charging systems are in this link.
If you have the B.I.M. instead of BIRD charging system the B.I.M. could be installed backwards, as pointed out in this link.
These links are in this link sticky.

[mre]

Tok is a small in eastern Alaska. Kind of an interesting place, at least to me.

We have 50 amp service so the batteries were charging all night.

In the morning just before leaving, I started the generator. Once it kicked in, we started the engine and the chassis battery dropped and would not charge after about 20-30 minutes. I shut everything down. What I ultimately found was that the generator would charge with the engine off and all I had to do is turn the key to the run position (engine not running) and that would stop the generator from charging the chassis battery. Total opposite of what occurred the day before when the generator was charging the battery while driving down the road.

Originally Posted by twinboat

How long did you have the generator running before you returned to the CG ?

I don't know what Tok is, but if you were dry camping, your battery isolation/combining system will not allow your inverter/charger ( running off the generator ) to combine the battery banks, so the chassis batteries will charge, until the house battery bank was charged up to about 75% to 80% or 13.6 volts.

Depending on the house battery voltage at startup, even if the house bank was charged on shore power, there could be a 10 minute delay thru the isolation system.

[mre]

Originally Posted by 007";4881795]Your battery charging systems are in [B][URL="http://www.irv2.com/forums/f103/12-volt-electrical-and-wiring-systems-in-your-newmar-379149.html

this link[/URL][/B].
If you have the B.I.M. instead of BIRD charging system the B.I.M. could be installed backwards, as pointed out in this link.
These links are in this link sticky.

Thanks. For me, this may take some time to read and understand. This is unchartered territory.

["007"]

Just found this one tonight has to do with fuse in charging system blocking alternator charging.

[dms]

On my 2016 MADP, I had the same issue, wherein voltage kept falling toward 11.9 volts. Called FL hotline and the tech told me to hold the bridge switch in to keep voltage up from the house batteries, until I reached a FL dealer up the road. Pulled into a FL dealer in Maryland.

The tech said he probably knew how to fix the problem, as he has seen it before. There is a signal wire from the alternator to the starter which then goes to the ECU, and they have had bad connections on this wire at the starter. He checked it out and sure enough, that was the problem. He cleaned the connection at the starter and re-installed it with loc-tite. No more issues after 2 years. 30 minute fix.

[mre]

Originally Posted by dms

On my 2016 MADP, I had the same issue, wherein voltage kept falling toward 11.9 volts. Called FL hotline and the tech told me to hold the bridge switch in to keep voltage up from the house batteries, until I reached a FL dealer up the road. Pulled into a FL dealer in Maryland.

The tech said he probably knew how to fix the problem, as he has seen it before. There is a signal wire from the alternator to the starter which then goes to the ECU, and they have had bad connections on this wire at the starter. He checked it out and sure enough, that was the problem. He cleaned the connection at the starter and re-installed it with loc-tite. No more issues after 2 years. 30 minute fix.

What and where is the bridge switch?

[dms]

The "bridge" switch is a momentary switch on the dash that ties the house batteries to the chassis batteries. Its purpose is to allow cranking the engine in the event the engine batteries are dead. When depressed, a solenoid is energized that parrallels both battery banks together.

In your case, it allows the house batteries to literally feed the engine since the alternator circuit isn't charging. This is temporary, since eventually the house batteries will deplete. You can then run the generator, allowing the converter to charge the batteries and extend the time you need to get to a repair shop.

Rather than continually hold the bridge switch, put a pen knife or toothpick at the top of the switch button to hold it in until you reach a shop.

[mre]

Originally Posted by dms

The "bridge" switch is a momentary switch on the dash that ties the house batteries to the chassis batteries. Its purpose is to allow cranking the engine in the event the engine batteries are dead. When depressed, a solenoid is energized that parrallels both battery banks together.

In your case, it allows the house batteries to literally feed the engine since the alternator circuit isn't charging. This is temporary, since eventually the house batteries will deplete. You can then run the generator, allowing the converter to charge the batteries and extend the time you need to get to a repair shop.

Rather than continually hold the bridge switch, put a pen knife or toothpick at the top of the switch button to hold it in until you reach a shop.

Okay. I believe you mean the "battery boost" switch. Correct?