I must have the market cornered for shorted diode trio's on the 2400-2600 JB series of L-N alternators as I have three of these that will pull batteries flat pretty quickly. One even warms it's case. Is this a known thing with the brand or am I just unlucky? I have an older Delco 25SI that does the same thing although it takes just about three weeks to pull a pair of group 31 top post batteries flat. I have installed battery cutoff switches on most trucks but am starting to repair these alternators now having some time.....
I never did like that brand of alternator. All those wires and no explanation as to how that system was supposed to work. In the trucks I had to work on the units never seemed to have enough capacity to charge the batteries when all the lights and the heater were on at the same time. People would bring the truck by without the trailer and everything would work. Everything checked out fine. Then they went and hooked up the trailer and the problems showed up that night. Bring the truck back again without the trailer and it was all my fault. Did I ever mention that I hated working on trucks.
Even in the 80s early 90s we dragged most L-Ns off and installed 25SI Delco Single Wire units. Was a slightly Smaller frame style, 27SI? maybe 20SI? we used as well.
The 25SI is replaced with the 26SI and I understand is a heavier rated unit. Same physical dimensions IIRC using the same SAE mounting style so probably going that route. I don't know about these L-N alternators as they are about a hundred in parts to rebuild and I'm really uncertain about the chinese influence on the electronic components. Really don't know much about Remy since the selloff from the Delco line, but I purchased a reman Delco 10SI for my Worthington compressor and the package was emblazoned, "Remanufactured in China" on the box. However with Advance now owning Carquest, I expect no less. That alternator lasted just about two months till it *hit the bed and I replaced it with an old Delco unit which works fine after I rebuilt it on the bench. Carquest refunded the expense of the alternator purchased from them and let me know failure is better than 50% in a year since the takeover. Not ripping on any vendor; just repeating what I was told.
27SI is the replacement I preferred. The 25 was a good unit but a lot more expensive.
Installed several of these LN's AVI55J 170 amp no issues, Freightliner was selling them for $130.00 bucks for awhile. Internal fan type.
Still have no love of LN Products, starters included.
Well! then I guess that's all DM has to say about that, Not no way not no how-just like the door man in the Wizard of Oz.
Sorry, just no love lost between myself and LN, fleet I worked at tried them in mass numbers 1978/79/80, we ended up changing most Alternators in less than 150,000 miles, starters were random fails and no warning. Just cannot get a good feeling on them.
Well things do change and Leece Neville builds a pretty good alternator these days, years ago not so good.
I replace every LN I run across and still do. Never had good luck with those.
Would have to work hard to change old hard feelings. Corn Queen sent us Pallets of DR MT40s and 27SI Alternators back then, every wagon with the LN series had to be swapped for a warranty program after we had changed a wad of the LNs to new LNs. Even I was getting a work over trying to keep customers happy with loads of fleet trucks just popping thru to get swaps. If they are making a better product good for them, but that bad taste still lingers.
I replace every Delco I run across and still do. Never had good luck with those.
I still have the original L-N 2500JB on my R model and the truck is a 1980. I purchased it in 1983 and knew the original owner and he never changed it. Still works like it always has. L-N on other trucks deplete the batteries, but still charge well. Just can't leave it in the system or the next time you go to start the unit, out come jumper cables..... I found an old "Prestolite" branded 12V neg ground alternator in the garage today but don't know any history, so going to evaluate it later.
Hey DM look what I did, I put one of those nasty old Leece Neville alternators on you know what.
If they work not a problem, when they don't on a regular basis and my hands were in there swapping them they were. Have a single Wire 24V to go on my old Allis loader soon as I can get it into the shop. Converting from a Generator to single Wire Alt, NOT a name brand but was thru the local AG dealer. Only 45A but only need to recharge after a start, no electrical accessories. I am working to get it moved up to house and into shop for a rails swap, some cooling system and structural work some time next week. Also have that resealed trans to swap out then reseal the pulled unit for spare.
It's always interesting how some people have problems with one brand of anything and someone else will swear by that same brand. One I have seen on a couple very different forums lately is about spark plugs. One guy will hate Champions, another hates Autolites and another NGK. Now I could understand if we were talking JCB's
Have had various luck with all the above spark plugs. Used ACs for a LONG time, quality suffered so went back to Champions, they too dropped in value so swapped again to NGK then Motorcraft and now back to Champion. Runs in spurts. Used to dearly enjoy repairing those seldom failed Prestolite ignitions and charging systems but a buy out occurred cannot remember by whom and that line went to crap for a LONG time, see a few odds and ends repair parts around and are back to some level of quality. As with the battery we just had Fail, seems FOMOCO on a stamp and the quality is seriously lacking, once again that moving target rolls around the wheel.