malcoll Posted May 30 Share Posted May 30 Wife and I are on a trip and traveling down to highway we had to slow down...engine RPM drops below 1300ish and the Alt Warning buzzer starts going crazy and Allison transmission pops in and out of 6th gear, I look down and Guage says 10v.....I speed up, once I get over 1300ish RPM buzzer stops and all seems normal with transmission except Guage still reads 10v....house volts is 14.38v...I do have generator running to run house A/C. Any ideas...think I need an alternator? I'm hesitant to shut the engine down that it won't restart. Thoughts? Link to comment Share on other sites More sharing options...
waterskier_1 Posted May 30 Share Posted May 30 Turn off the generator and see if the issue resolves. - Rick N 1 Link to comment Share on other sites More sharing options...
malcoll Posted May 30 Author Share Posted May 30 Hmmmm interesting ..it popped up to just under 12v, then dropped back to just above 10v....and kinda fluctuating up and down. If I turn on headlights Guage drops to just above 10v....running about 1700 rpm right now... Link to comment Share on other sites More sharing options...
malcoll Posted May 30 Author Share Posted May 30 I have a solar system too, and when I bought the coach over two years ago the PO told me sometime the ALT CHARGE light would go on with buzzer but turn on headlights and it will stop....it has happened randomly over the years but lately a bit more often and at those time the alt gage would read around 14v.......more recently I get this random low Guage reading...I'm thinking my alternator is going out.....what alternator do I buy to replace it? Link to comment Share on other sites More sharing options...
jacwjames Posted May 30 Share Posted May 30 You alternator may be bad. Mine failed in ~2012, I pulled it off and had it rebuilt, cost ~$185 at the time. Link to comment Share on other sites More sharing options...
Dr4Film Posted May 30 Share Posted May 30 Sounds like your alternator is or has failed. Do NOT drive with headlights on. Use a 6 gauge jumper on your Battery Isolator Relay to jump both House and Chassis Battery Banks together and run your generator to keep the chassis battery above 11 VDC. Below that your Allison with shut down or go wacky. 2 Link to comment Share on other sites More sharing options...
malcoll Posted May 30 Author Share Posted May 30 I think my system charges house and chassis batteries? Link to comment Share on other sites More sharing options...
Just Jim Posted May 30 Share Posted May 30 I second the idea of taking the old off and getting it rebuilt. These things have some crazy systems on them that can create more problems. I bought mine a read ago and that was the first thing I did was have the alternator rebuilt. I was fortunate that the alternator shop was very familiar with it and he upgraded it from 200 amps to 320. Link to comment Share on other sites More sharing options...
jacwjames Posted May 30 Share Posted May 30 11 minutes ago, malcoll said: I think my system charges house and chassis batteries? Not sure on your system, it may charge both sets of batteries, my 2002 does/did. But with mine it relied on a Lambert 415 maintainer to maintain the chassis batteries. The Lambert would trickle charge the chassis battery when plugged in or on generator but I don't think it could keep up with amp requirements while driving. I was having trouble with my charging system and decided to upgrade to a Bluesea MLACR latching relay. Link to comment Share on other sites More sharing options...
Benjamin Posted May 30 Share Posted May 30 Lots of things that could be happening. I'd want to leave it running, and go check the voltage at the chassis battery terminals, if that's less than 13, then check the voltages on all the terminals on the back of the alternator. Everything else is guessing. 1 Link to comment Share on other sites More sharing options...
malcoll Posted May 30 Author Share Posted May 30 Welp.....stopped for fuel and the alternator bottomed out....couldn't engage the transmission.....a truck repair shop around the cornering helped us limp over to their shop and the will replace the alternator in the morning.....so tonight is boondocking night running genny! Link to comment Share on other sites More sharing options...
Dr4Film Posted May 30 Share Posted May 30 (edited) Good luck at the shop. Hopefully they will know the intricacies of the Leece-Neville Alternator and not just throw any Alternator on your engine. The right way is to have it rebuilt with genuine LN parts, all parts not just the failed ones. I would have opted for running your coach with the jumper and using the generator until you were able to get to a shop that can do the right job. I have driven hundreds of miles that way when we were on our way to Alaska. Eventually had the alternator rebuilt in Anchorage AK. Edited May 30 by Dr4Film 2 Link to comment Share on other sites More sharing options...
Frank Bergamo Posted May 30 Share Posted May 30 Make sure you keep your old one. Have it rebuilt and keep for a spare. 1 Link to comment Share on other sites More sharing options...
malcoll Posted May 31 Author Share Posted May 31 We are replacing this morning with a Delco Remy 28Si......I am kinda hovering over the tech I assume the DUVAC wire goes to the "s" terminal, then the ignition to "i" terminal...the remaining small wore goes to the "r" terminal...and the Battery Charge and Ground are obvious. Right? Link to comment Share on other sites More sharing options...
Just Jim Posted May 31 Share Posted May 31 Good luck with the replacement. Nothing is obvious with the wiring. It is why many suggested the rebuild option Link to comment Share on other sites More sharing options...
Dr4Film Posted May 31 Share Posted May 31 (edited) Is the Delco Remy 28Si a Duvac Alternator? If not then you are on your own! Good luck! Edited May 31 by Dr4Film Link to comment Share on other sites More sharing options...
jacwjames Posted May 31 Share Posted May 31 Here's a graphic I found that shows the comparison between a Leece Neville and Delco Remy alternator. Has the same number of wires, different locations. DUVAC system - Leece Neville or Delco Remy.pdf Link to comment Share on other sites More sharing options...
Benjamin Posted May 31 Share Posted May 31 (edited) 1 hour ago, malcoll said: We are replacing this morning with a Delco Remy 28Si......I am kinda hovering over the tech I assume the DUVAC wire goes to the "s" terminal, then the ignition to "i" terminal...the remaining small wore goes to the "r" terminal...and the Battery Charge and Ground are obvious. Right? Yes, you got it. If the tachometer doesn't work after the swap, they got the wire to the R terminal wrong. If the battery goes dead overnight, they mixed up S and I. If your old one was leece neville, and they didn't diagnose the alternator besides the no charge, then here's how to check it yourself : https://wiki.foreforums.com/lib/exe/fetch.php?media=technical:electrical:troubleshooting_leece-neville_alternators.pdf the full field test is the main thing in that link, that proves the alternator is basically sound, and the issue is in the voltage regulator, or wiring. There are other tests, youtube etc. if you want to just replace the broken parts to keep a spare Edited May 31 by Benjamin Link to comment Share on other sites More sharing options...
TomV48 Posted May 31 Share Posted May 31 23 hours ago, malcoll said: I think my system charges house and chassis batteries? Have you considered the simple answer and just pulled your batteries out and tested them. In the four years since I swapped out the truck batteries I've noticed they've started to fade. Now the alternator drops down if I have the headlights on suggesting to me that the battery can't carry the load anymore. I also find that sometimes when it's been sitting awhile especially if I don't use the truck battery shut off switch that I have a hard time getting the engine to start. I don't worry because have a great big chassis battery bank and I can jump it over when I need to but it sounds like you should check the obvious first. Link to comment Share on other sites More sharing options...
Tom Cherry Posted May 31 Share Posted May 31 15 minutes ago, TomV48 said: Have you considered the simple answer and just pulled your batteries out and tested them. In the four years since I swapped out the truck batteries I've noticed they've started to fade. Now the alternator drops down if I have the headlights on suggesting to me that the battery can't carry the load anymore. I also find that sometimes when it's been sitting awhile especially if I don't use the truck battery shut off switch that I have a hard time getting the engine to start. I don't worry because have a great big chassis battery bank and I can jump it over when I need to but it sounds like you should check the obvious first. On 5/30/2024 at 4:15 PM, Dr4Film said: Sounds like your alternator is or has failed. Do NOT drive with headlights on. Use a 6 gauge jumper on your Battery Isolator Relay to jump both House and Chassis Battery Banks together and run your generator to keep the chassis battery above 11 VDC. Below that your Allison with shut down or go wacky. OK…first. NAPA makes a #2 Jumper 781144. That will, temporarily, resolve your issue. IF I AM CORRECT…you have a White Rodger’s Boost Solenoid. Use the NAPA to Jumper across the Boost Solenoid. OK….next up… and this is tricky. We (or the Staff and Moderators) need some pictures of your system. There was a change in the early 2002 Windsors. The prints show the Boost Solenoid. There is also a “Charging Relay or Module” on the white (?) Panel or label for the electrical bay. Find it. Is it still there. It is an Intellitec module. It has 5 terminals. Ground, House Bat, Solenoid/Rely, Ignition and Genny. Has it been gutted or removed? Post a Picture. Your system is designed to CHARGE both ways….as you drive…Chassis alternator provides current to Chassis. The White Rodgers is supposed to be CLOSED…and that charges the House. Conversely….when on AC / Genny…the White Rodgers is ALSO closed…and you get power to the House….which is then sent to the Chassis. SO…before doing anything, to get you running….install the Jumper. That is the SAME as a Jumper Cable. If you have the “Voltage Drop” issue….then, with the JUMPER in place….you can disconnect the Positive from the Chassis. The engine will be running from the House…and being recharged from the Alternator. IF there is a failure in EITHER of the Chassis Batteries….and they are removed….and all is well…then you have DEAD short or a bad cell(s) in one or both of them. This is a FUNCTIONAL load test…not some cheap tester that usually says….BUY MY NEW BATTERY(s). IMPORTANT. Assume you have TWO positive cables to the dual Chassis bank. Pull one….insulate it. Use a plastic bag…then some shop towels and a strip or two of electrical tape….secure the cable…repeat for the other. Some use a plastic mixing bowl…just make sure they don’t bounce….that way, safe to drive. That’s it. Link to comment Share on other sites More sharing options...
malcoll Posted May 31 Author Share Posted May 31 Thank you all for the great ideas and recommendations! They installed the 28Si as outlined, got it started and it was charging properly....off I went for the remainder of our journey to Banner Elk......got here.....got the coach in it's spot.....turn the key off......and engine won't shut down. So I found our error...the ignition lead is apparently not supposed to be connected in this conversion....clearly I did not know that, nor did the repair shop. So how does one shut down an ISL 370 that is get voltage from the alternator? I have ideas....pull fuse for ECM is one....I called the shop they said pull the air cleaner and put something over the opening and choke out the engine (I don't like that one)....any ideas? Link to comment Share on other sites More sharing options...
jacwjames Posted May 31 Share Posted May 31 What if you shut off the chassis battery disconnect and/or pull a cable. Link to comment Share on other sites More sharing options...
Dr4Film Posted May 31 Share Posted May 31 Google runaway diesel engine. Link to comment Share on other sites More sharing options...
Benjamin Posted May 31 Share Posted May 31 Pulling the ECM fuse should work. If you can get at the alternator, snip the wire connected to the I terminal, and add a resistor between the wires you snipped to prevent that from happening again and keep the rest of the system working as designed. Link to comment Share on other sites More sharing options...
malcoll Posted May 31 Author Share Posted May 31 I found the fuse that shut it down. Disconnected the ignition lead from the 28Si and taped it up out of the way and not able to short out.....all seems to work as expected now I deeply appreciate allthe great ideas, recommendations and advice on this...what a great community. I'll start contributing more and maybe we can all get together somewhere for a rally, I am up in Banner Elk this weekend with a gathering of Porsche 928 owners! Link to comment Share on other sites More sharing options...
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