2003 Monaco Dynasty Alternator issue

[texnet]

I recently purchased a 2003 Monaco Dynasty 42' Countess. The dash gauge on the dash was showing about 10vdc so I checked the voltage at the batteries with the engine running and found it to be 12.4 volts. I removed the Leece Neville 14884JB alternator and took it to an authorized Leece Neville distributor who tested it to be bad. They rebuilt the alternator, said the stator was burned up, and I reinstalled it this evening. The dash gauge is now a little higher at about 10.5 volts and the voltage at the batteries, with the engine running is still in the mid 12vdc range. While it is possible they did not fix the alternator I believe it to be something else as I am sure they tested it on the bench. I do not have a chassis wiring diagram for the coach. I am a mechnical and technical person but without schematics I am not sure where to start looking!

If anyone has the chassis wiring diagram please let me know and if you have any suggestions of where to start troubleshooting please reply!

[JeepTJ5]

I'd suspect that the alternator still isn't working correctly. It's possible that you have some large current draw with the engine running, but it's unlikely. If everything that is not necessary to keep the engine running is off, then you should see the voltage above 13. That alternator is probably 160 amps, or maybe more (that's a big coach) and with nothing but the engine drawing current, then the battery voltage should be 13+. If you can measure the voltage at the output terminal of the alternator it should be a few tenths above the battery voltage due to the voltage drop in the wire to the battery. If it is identical then there's no output from the alternator. Hope this helps.

There are Delco Remy replacements much cheaper than the Leece Neville. My coach had a Leece Neville that was only available thru Monaco, and they wanted over $1100 for it. I got the Delco Remy 22 Si (160 amps) for $180, and it is a direct bolt-in replacement.

Good Luck.

[walt2137]

Ronnie Monaco Mama started a file on the Monaco wiring diagrams when she was taking care of this forum and I did a search and could not find them she will probably see this and give us a answer. I do have a wiring dia on a 2000 dyn but not sure it would help.
E mail me at walt2137 @ yahoo.com if you think it would help

[texnet]

Quote:

Originally Posted by JeepTJ5 There are Delco Remy replacements much cheaper than the Leece Neville.

I read the threads on the Delco replacement and checked into it. Mine is a 200 amp and thus I would need a 28SI which runs about $350 and would take a week to arrive. The cost to rebuild was $425 and it was done in less than 24 hours so I went with the rebuild. Just an FYI for anyone needing a 160amp, I did see the 160amp 22SI on sale at the local Fort Worth, Texas Freightliner dealer for $159.95.

[texnet]

Quote:

Originally Posted by walt2137 E mail me at walt2137 @ yahoo.com if you think it would help

Thanks, Message sent :-)

[Twomed]

How are the chassis batts?? I would pull them, slow charge, let them sit, then test them properly, hydrometer and load test to rule out any problems. You could burn up your new alternator trying to charge bad batt very easily.

PS...Monaco dash guages are notoriously unreliable. Check output at the batts with a meter before you do anything else. Also check voltage at 1000rpm, not idle. Maybe you are fixed and don't know it yet.

[86 Cavalcade]

Ronnie, I put a Delco 28si in my 2001 Diplomat. If you buy one of the Delco's make sure you get the right model. The model I bought is the one that has the "DUVAC" wire, except Delco calls it a battery sense wire. I would test the Battery Isolator if your coach is equipped with one. That is the big blue item that has cooling fins. The alternator #2 AWG wire lands on the center terminal, if you have 14 or so volts on this terminal when the engine is running test the other terminals to see if you have voltage that is 13.5 to 14 volts on the other terminals. These are solid state devices and they have about 1/2 volt drop across this device. You might have a blown fuse in the DUVAC wire circuit, or in the ignition circuit that goes to the alternator. On my coach the tach signal fuse, and the ignition fuse's ( 5 amp) were inline back at the alternator. The DUVAC fuse was a 20 amp fuse in my battery compartment. Good luck, George

[texnet]

After futher investigation I found the 200 amp battery isolator center post burned to a crisp. The center post is where the alternator + lead goes to. Hopefully the isolator was the cause of the problem and not the results of another problem. Headed out to get a new cable made and search for a isolator!

[texnet]

I was unable to find a 200 amp battery isolator in the local Ft. Worth/Dallas area but did find one out of state and it will be here in the morning. I also had a new 10 foot cable made. The one that goes from the alternator to the alternator post on the isolator was fried for about 3 inches from the isolator. Everything is back together except for installing the isolator. Will post the results tomorrow after it is installed.

[Airtool]

Have you checked to see if the exciter wire is OK. Your alternator shop should be able to point out the proper terminal.
This terminal only needs to have voltage when the engine is started,it is generally supplied from a point that has power only in start, not in the run position of the ignition switch.
The voltage you are reading at the alternator should read 13.5 volts and the reading you are getting is common when the alternator is not energized.

Dick.

[texnet]

I thought I would update this thread on the total solution to the problem. First, I had the alternator rebuilt as the stator was burned out. I installed the alternator and new belts and still had no apparent output from the alternator. The alternator did get abnormally hot so I shut the engine down and did some more troubleshooting. I found the solid state battery isolator with the center post (where the 2/0 cable comes from the output of the alternator, burned and the cable burned. I ordered a new 200 amp isolator, had a new 10' 2/0 cable made at a local NAPA and reinstalled... still no output. Took the alternator back to the place that rebuilt it to find the stator and one of the diodes burned out. They put in new parts and I reinstalled this afternoon. Everything is now working properly including the dash gauge!! Moral to this story... when you find an alternator not working make SURE you check all other components PRIOR to installing the new alternator. Could save you additional $$$ and time!

[moisheh]

texnet: Glad all is working for you. You were correct in rebuilding vs. replacing with a Delco. The Dynasty's come with an awesome Leece Neville. Changing to a Delco is like trading your BMW for a Skoda or a Trabant! Truckers consider the Delco to be disposable. They are cheap to buy but do not last very long. There is a reason why LN's are used in emergency vehicles.

[Mike Canter]

Ronnie, I am glad it is finally fixed. Now just a word of caution here.....make sure all those big cable connections are tight. I would guess that the problem with the burnt wires and isolator was because of a loose or dirty connection that resulted in high resistance and got real hot. The other thing is that lug on the alternator it is important to make sure that is tight with only the nut turning and not the whole lug. I read the below article and I was really surprised on how many fires there are because of what happened to your alternator and wiring.

Read the first couple of pages
http://www.cvsa.org/publications/gua...supplement.pdf