2001 HR Imperial House battery charging issue

[floydfowler]

1 hour ago, kaypsmith said:

It's only a maintainer designed to keep the battery charged that is not receiving a charge from either the alternator or inverter, if charge is not happening on either then it will not try to charge . If you notice in the original picture there are three small boxes side by side, the one in the middle is marked isolator lockout, the one to the right is not marked, but your schematic signifies that it is a slide lockout. Both of these are connected to the LE415 through a ground bus bar, the ground bus bar is activated by the negative terminal on the maintainer, it appears that the ground bus bar is isolated from chassis ground unless it sees ground from the maintainer. In turn, the large relay, the one with two large wires and two small wires is not receiving ground (small wire on left is normally positive) while a relay depends on both ground (small wire on right) to be activated at the same time otherwise it will not close. The closing of this relay is what causes both chassis and house batteries to combine to maintain charge when the alternator is producing current. If you notice on your schematic someone has penciled in that this same relay is also your auxiliary battery combiner (the switch inside) which actually overrides the lockout system. The lockout goes directly to a delay relay that actuates the large relay by means of signaling the ground ( - ) side of that relay. Hope this helps. Rich emailed me earlier to tell you that he has gone to doctor today and asked me to try to help with your problem while he is away.

Rich is really a prince of a guy!!  Yes, this does help me to get all of this into focus.  I had just confirmed that the white ground wire  going to the center terminal is connected to chassis ground  and took resistance readings between the terminals of the green relay with the wires disconnected as instructed yesterday by Rich  Today I got different readings from those given to Rich as follows: Pos test lead to center terminal and neg lead to lower terminal I get 0.59 m ohms, and with neg lead to top terminal I get "open".  With neg test lead on center post and pos lead to lower post I get open, and with pos lead to top post also open.

The trouble shooting info you referred me to refers to the Battery Isolator testing with  ohm meter says I should be seeing zero or near zero ohms to both battery terminals with neg lead on center post but I am seeing the chassis post (top) as open.  It also indicated that the terminal 1 (center??) should be connected to the alternator but my center terminal is connected to chassis ground.

I am going back out to the coach now to recheck the voltage readings at the alternator as outlined in the tips.

[floydfowler]

OK I checked the voltages at the alternator terminals:

Alternator:
There should be no voltage between the alternator + and – terminals
either with the key on or off unless the engine is running. If voltage is
present check the connections to the battery isolator and the functionality
of the isolator if connected properly. With ign. off, I read -12V ., with ign. on,  read - 12V
Ignition Terminal:
There should be no voltage to the ignition terminal with the key off. There
should be 12V to the terminal with the key on (with or without the engine
running).With ign. off, I read -0.311 V and with ign on, I read -12 V between ign terminal and negative alternator terminal and 12.2 volts between ing terminal and chassis ground.
DUVAC Terminal:
The DUVAC terminal requires 12V (coach battery voltage) to function, this
functions as the “battery sense.” Depending on the application this may be 12 V with key on as some vehicles have a relay with the ignition system.

I read 0 v with ign off and -.15 v with ign on.  from duvac terminal to negative alternator terminal but I also read 12.8v between duvac and chassis ground.

It is obvious the the negative alternator terminal is not grounded to the chassis.

[dickandlois]

Floyd 

            Alternator:

Does the large alternator battery cable read positive 12 volts?  when the engine is NOT Running ? The one that is missing in the drawing at the large terminal?

        I have never run into a positive grounded Alternator on a US built coach or car.

                         With ign. off, I read -12V ., with ign. on,  read - 12V
Ignition Terminal: ???

                         With ign. off, I read -0.311 V and with ign on, I read -12 V between ign terminal and negative alternator terminal and 12.2 volts between ing terminal and chassis ground.
DUVAC Terminal:???

                           I read 0 v with ign off and -.15 v with ign on.  from duvac terminal to negative alternator terminal but I also read 12.8v between duvac and chassis ground.???

t is obvious the the negative alternator terminal is not grounded to the chassis.   The alternator should be grounded to the Chassis, when it is bolted to the engine bracket.

SO ! Using your OHM meter read the resistance between the alternator. IT should read zero !!! or very low reistance -reversing the black and red meter leads and the resistance should read zero .

IF it does not then we need to see what is going on.

The Diode readings do not look right !!!!!

From ground terminal(center terminal) to both outer terminals using the red lead (the meter should read high resistance - 100 k to meg ohms.  Reversing the red and black locations and the meter should read somewhere between 500 to 1,500 ohms.

The way the battery maintainer is wired from my view point would never charge the batteries. And if you read 14 volts or more at the coach and chassis batteries . The battery maintainer would slowly discharge them.

Rich.

NOTE. I did read your feedback about the resistance, want you to retest using the instruction offered.   One of the circuits reads open both ways if I,m reading things right. I'm getting a bad feeling and I want to be wrong about the wire ring.

[floydfowler]

Rich,

First I must thank you for being so thoughtful in getting me help in your absence.  I hope all went well with your appointments.
Now let me tell you how dumb I really am....I was taking alternator reading upside down and confused positive and neg terminals of the alternator.  Rechecked readings correctly and now I read positive 12.6 volts between pos and neg post on alternator and 12.6 volts between positive post and chassis ground. Also, read 3 ohms between battery neg post and chassis ground.

Hope this makes more sense but I lam still concerned that I get 12v across the pos and neg terminals as the tech tips says it should be zero.

[floydfowler]

correction, should have been 0.3 ohms between the battery neg post and chassis ground.  

[kaypsmith]

Floyd, please remember that the green LE415 is not the isolator, it's a battery maintainer. The isolator on your coach is the big relay which is also your battery combiner, it's a dual purpose relay used to combine battery banks both when you push the button and also when the coach is running and the alternator is producing current. When alternator current is not present, the relay should remain open, while coach is running, it should close, this is how the alternator is able to charge the house batteries. To test while running, both large terminals to chassis ground you should see 12+ volts, when not running, only one side will be hot if all is correct.

[floydfowler]

I just checked the voltage at the large relay terminals with engine off, 12.9 volts to chassis ground at both terminals. With engine running, 14.3 to both terminals.

[floydfowler]

34 minutes ago, floydfowler said:

I just checked the voltage at the large relay terminals with engine off, 12.9 volts to chassis ground at both terminals. With engine running, 14.3 to both terminals.

Could this be related to the 12 volts I see across the alternator terminals when I should not have any voltage across the terminals?

[kaypsmith]

Yes, the isolator relay is not unlatching now causing the voltage to carry over to the alternator (not good). Now, remove the ground wire from the LE415 and perform the same test and let us know the results. Forgot to say why not good, because the isolation circuit is not unlatching will cause your chassis batteries to discharge while not running if demand exceeds the inverter ability to keep up, or no shore or generator power.

[floydfowler]

53 minutes ago, kaypsmith said:

Yes, the isolator relay is not unlatching now causing the voltage to carry over to the alternator (not good). Now, remove the ground wire from the LE415 and perform the same test and let us know the results. Forgot to say why not good, because the isolation circuit is not unlatching will cause your chassis batteries to discharge while not running.

Took ground wire of LE415, no change. Same as before, voltage to both terminals of relay to chassis ground.😞

[floydfowler]

I guess I had not noticed the discharge of the chassis batteries because I always plug in to shore power while parked .

 

[floydfowler]

I ran across these interesting photos of 2002 Monaco panels that are very similar to mine except for the item no. 7, relay, Bidirectional Isolator.  Maybe an improvement?

 

 

1 Electrical Panel Passenger Side 2.pdf 1 Electrical Panel Passenger Sider 1.pdf

[kaypsmith]

Okay, now put the ground wire back on the LE415, and follow that ground wire over to other end, the wire is supposed to be connected to another relay, that relay is a time delay relay, unplug that wire and retest to see if the isolator drops voltage on one side. If it doesn't drop voltage then next go to the relay marked battery isolator lockout, and unplug the white wire terminal, being sure to mark and remember which spade that it goes back to and retest and let us know the results. Great work on your part, thanks for keeping up.

[floydfowler]

I will get  right on it in the morning if the weather will cooperate...lots of rain predicted here. 

Many thanks again for all your help!!

[kaypsmith]

Yep, calling it a night here also, incidentally, that isolator relay should become unlatched with the ignition switch turned off. You should not see voltage on both large lugs with the ign off, if you do something is either shorted or somehow miswired. I'll check back in the AM. Rain is also predicted here, and I am going to pull my generator as soon as weather permits, it has a leaking radiator that occurred a couple weeks ago while vacationing in Florida.

[dickandlois]

6 hours ago, floydfowler said:

correction, should have been 0.3 ohms between the battery neg post and chassis ground.  

Floyd, From the reading you posted on the drawing it looks like the diode connected between the chassis and center lead has failed. That being the case, think you will need to replace the battery maintainer. Both sections between the center and the coach side and the chassis side should read the same or close to each other. Lost internet in a rain storm for a few hrs. LOL

This has happened when we get heavy rain over the last 5 months we have been parked.  This time it was very inconvenient not being able to fallow the posts. Gr. 

Just want to make sure the coach and chassis wires where disconnected during the test.

So Glad Kay was able to be a backup. 5 more appointments tomorrow. Hope the doctors will cut me loose so we can get back home to western  N.Y.

I will be looking at the specs on the battery maintainer in the mean time.

Your willingness to keep hanging in there has been outstanding ! Reversing meter leads has happened to everyone using a meter at times. All you can do is laugh at yourself and keep on going.

Rich.

[kaypsmith]

Good morning, after the above tests, I only have one more. With the ignition off and key removed, and shore power disconnected and generator off, please use the domestic kill switch and place in the off position. With the kill switch off in the off position check the voltage on those large terminals, both sides to ground. The chassis side should read 12+ volts and the house side should read 0 (not uncommon to see .354 or some other crazy low number). Please record the results and let us know. Next, start the engine and again check voltage on both terminals to chassis ground and let us know the results. When the kill switch was on, we should have been seeing about the numbers posted because both battery banks were incorporated, though it is uncommon to see two banks when disconnected from each other be exactly the same. The test that I am having you do now will tell if the relay is actually working or not. Don't forget to turn that domestic switch back on after the test and of course plug back shore power. Good luck.

[floydfowler]

Good Morning Kay,

Before I get started with the above tests  I wanted to tell you about my latest weird happening.  First I will explain that the step cover at passenger's seat is normally retracted with chassis battery on and extends when the chassis battery is switched off. Last evening after I took the voltage readings at the relay I realized that with chassis battery switch off the step cover did not extend but the ignition and dash instruments had no power. I did not think much about it since the relay had power on both terminals.  I woke up in the middle of the night thinking about the problems and suddenly remembered that I had left both battery switches on. Then I began to worry that I might be draining the batteries as the shore power was also off (to eliminate the inverter/charger from the mix) so I got up and went out to turn them off (3:00 am) and as I did I heard the step cover closing. Switched chassis battery back on and cover retracts as it always has. Really getting curious now, I checked the voltage from chassis ground to both posts of the relay and NO VOLTAGE!!  Still had 12v from neg terminal to positive terminal on the alternator. I just rechecked it to be sure I wasn't sleep walking or dreaming and I get the same results. 

I will now recheck for voltage at the relay posts with engine off and engine running and the ground back on the LE 415.

Floyd

[floydfowler]

54 minutes ago, floydfowler said:

Really getting curious now, I checked the voltage from chassis ground to both posts of the relay and NO VOLTAGE!! 

That is with both battery switches off and measuring from  relay post to chassis ground terminal in left side of panel. With both switches on I read 12.78 from house side to chassis ground and 12.62v from chassis post to chassis ground. 

[floydfowler]

Conclusion:  

With Kay's kind assistance we went through the system and determined that all is functioning as designed and batteries are getting required charge.

Ready for the road now!

Many thanks again to all who contributed !