Alternator Specs

[Bruce Benson]

We have had the alternator in our 2001 Marquis rebuilt twice and the last time the rebuilder removed the tag with the model, serial number and output on it.  It has once again failed, this time at the northern tip of Newfoundland.  Does anyone happen to have the numbers for the alternators used on this year Marquis?

Thanks,
Bruce

[Gerald Farris]

This should be all of the information that you need.

Leece-Neville
Product Specifications Spec Value
Item number A0012825LC
Sales number 2825LC
Series number 2500
Notes FOR BATTERY ISOLATED SYSTEMS. HAS SHORTER POSITIVE STUD THAN 2824LC., ISOLATED GROUND, REMOTE EXCITE
Volt 12
Output 160
Mounting style J-180
Dimensions in INCHES
Rotation BI-DIRECTIONAL
Housing coating RAW
UL Approved No
Mounting bolt size 1/2-13 UNC
Positive stud 5/16-18 UNC
Negative stud 5/16-18 UNC
Rectifier location INTERNAL
Shaft diameter .8743-.8753
Excitation type Ignition Excite
Regulator location Integral
Regulator number R240103726

Gerald

[Bruce Benson]

Thanks Gerald!

Bruce

[Gerald Farris]

The main reason for alternator failure on a motorhome is the use of the alternator to charge dead or discharged house batteries. The alternator charges the chassis and house batteries when the engine is running. If the house batteries are very badly discharged, the alternator will have to produce at maximum amperage for too long and therefore it will overheat and fail prematurely.

If you have been dry camping or have not been charging the house batteries due to restricted shore power, you should start the generator and charge the house batteries with the inverter untill the charge rate drops to the 75 to 90 amp range, depending on the battery bank and inverter that you have.

Gerald  

[Joey and Jackie Cashen]

Gerald, do you recommend carrying an extra alternator? If so, where would you purchase? I carry an extra water pump and have considered carrying the alternator. I have a C-12 in my 2001 Marquis.

[Gerald Farris]

I have the same engine in my 2000 Marquis and I do not carry an engine water pump, but I do carry an extra alternator. As I see it, the failure rate on a water pump is much lower than on an alternator, especially since the water pump on a C12 is driven from the timing case and does not have the excess pull of a fan belt (serpentine belt) all the time to cause bearing failure. However, if you are carefull not to overheat the alternator by requiring it to recharge a very large discharged battery bank (house batteries) it should give a long service life.

As far as a place to purchase a spare alternator, I purchased mine on E-Bay, but the alternator is used on many heavy duty trucks and can be found at truck parts suppliers as well as heavy duty automotive electrical suppliers.

I have carried that heavy alternator in my basement for 4 years and I have only used it to repair other owners coaches, never my own.

I would recomend carrying an extra serpentine belt though, because the C12 belt in a Beaver is usually hard to find. Although you only lose the AC compressor and engine alternator if the belt breaks.  You can still drive by running the generator to charge the house batteries and holding down the boost switch enough to keep the chassis batteries above 12V, and this method can be used to drive if the alternator fails, also.

If you were referring to a house water pump, it is a good idea to have one, although replacements are easily found.

 
Gerald      

[Bruce Benson]

OK, got the alternator fixed and we are back in business.  Gerald is correct in that you can easily drive the coach (C12) without an alternator.  Just take the belt off, use the generator and the house air.  

Now I have a confession, hard as it is to admit.  My first of three alternator failures happened when I jumped the toad off the chassis batteries with the coach engine running and let the cables slap together.  No, wait, that is not the confession, could have happened to anybody that rainy, dark, tired night.  (Idea - turn off the engine!)  

The problem was that by the time I removed the alternator in Jasper National Park in Canada, drove to Salem, Oregon, had the alternator rebuilt there while at the Monaco Rally, then reinstalled it, the meaning of the two pieces of tape that I had put on one of the two small wires became fuzzy and confused in my aging mind.  I ended up putting the wrong wire on the wrong terminal.  I had thus energized the field of the alternator full time for the next year when it once again failed.  I had it rebuilt a second time and dutifully reinstalled it exactly wrong once again.  It again lasted about a year with the field energized full time.  

This time I pulled a wiring diagram off of the Leece - Neville web site (thanks to Gerald providing me with the model #), checked the voltage on the two small wires with the ignition switch both off and on and realized my mistake.  The re-builder assured me that this would cause the failures that I have been experiencing.  

I am coming clean on this not because I suspect that others have made the same mistake but to clarify that it was never a problem with the quality or durability of the alternator.  This one was just very unlucky when it was assigned an owner!    

Bruce