Guest bobstromain Posted January 19, 2020 Share Posted January 19, 2020 While plugged in I measured voltage and had 13.5 on house and 13.3 on chassis. Unplugged for 4 hours or so and measured 13.1 and 12.9 volts. When starting the engine alternator only came up to 12, and alarm came on. Both sets of batteries were Showing 12.2 volts on the Aladdin. After allowing it to idle 45 minutes the alternator came up to 13.5 to 14. once it comes up I have no more problems until the next time I start the engine. I am assuming voltage regulator Is it built in to the alternator? I am not sure why once it comes up it stays up Bob St. Romain 04 Windsor Link to comment Share on other sites More sharing options...
David White Posted January 20, 2020 Share Posted January 20, 2020 (edited) Bob, I am assuming that you still have the original Leece-Nevelle alternator. In reading some other related posts, it appears the regulator might be built in. That could mean the alternator would need to be rebuilt. I’m not sure of that, so regulator location and replacement needs to be answered. However, maybe someone in the group might have thoughts on other problems which could cause your problems. It appears that all is well once you get on the road, the alternator output gets into the 14 range after a few minutes. So, at some point you are getting the proper charge at that time. Edited January 20, 2020 by David White Link to comment Share on other sites More sharing options...
Ivan K Posted January 20, 2020 Share Posted January 20, 2020 (edited) I think I would first try to figure out why house battery drops along with chassis batteries while starting. Maybe you use the boost function or have the solenoid or isolator malfunctioning? Once I understand that part, battery test (at the batteries) would be in order. Either the readings are wrong because of bad connections or the alternator can't keep up with bad batteries. BTW, the regulator is replaceable at top rear of the L-N alternator but I would not jump to conclusions until I know what's going on with the batteries. I don't know your coach but starting the engine would not normally drain a house bank unless you want to. The batteries could be weak and what you see after charging may just be a surface charge. Edited January 20, 2020 by Ivan K Link to comment Share on other sites More sharing options...
georgecederholm Posted January 20, 2020 Share Posted January 20, 2020 Try measuring the voltage at the alternator directly, right after startup. The Aladdin system is measuring voltage at a very different place in the circuitry. It’s not abnormal for the high draw of an engine start to pull down the chassis bank temporarily. It is very unusual for the house bank to have the same draw down, unless your battery isolation system is not operating properly. Do you have a Big Boy isolator or a different BIRD system? George C, 2005 Exec Link to comment Share on other sites More sharing options...
Guest bobstromain Posted January 22, 2020 Share Posted January 22, 2020 Thanks for the comments,. I have confirmed that the battery isolator switch is not closed, I have had the batteries load tested, and cleaned battery connections. Not sure how alternator is connected to house batteries when the engine is running. Problem is alternator alarm beeps and alternator only goes to 12 v. Aladdin showing 12.5 house battery and 12.3 chassis battery. After running a while (anywhere from 15-45 minutes) it all levels out. Due to an eye issue I am unable to pull alternator .....will get someone to pull it and have it checked and rebuilt. Amy future comments appreciated. Bob St. Romain 04 Windsor ll Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now