I'm trying to get to the bottom of some issues I am having with my father-in-law's 1990 Grand Villa. (3208 Cat) I can't seem to figure out if he wired something wrong or if there's just a problem with a component or several. I've tried following the wiring diagram and I think that things are connected in the right places so I thought I would reach out for some advice. It doesn't get used much, we spend a week at the lake during the summer and then a few short trips as well. I've attached a pic of the battery box as well as the wiring diagram. I'm well aware that the coach battery isn't what it should be. I'm considering putting a couple golf cart batteries in it's place with some sort of simple monitor so I don't drain them below 50%. Advice on that would be appreciated as well.
Here's what I've been seeing...
1. when connected to shore power it doesn't seem to charge the batteries. I can't seem to find where the charger is located to try to diagnose it. The alternator does charge however.
2. The shutoff switch on the floor to the right just inside the door in my opinion doesn't seem to operate correctly. when I turn it off, the only thing that goes off is the fridge....seems completely opposite of what it should be doing.
3. Shouldn't the batteries be isolated from each other? Last year during our week of camping; by the end of the week, both batteries got completely drained. Shouldn't it just drain the coach battery? During that week and knowing we have weaknesses in this system I had a battery charger plugged into my suitcase generator for most of the day time but they still went dead.
I'm not super savvy with electrical stuff but can usually figure things out with a little direction. I look forward to conversation with you all.
First, let me say that you are lucky to have the 12V wiring schematic. it will make sorting the electrical system much easier.
1. Your battery charger
should charge the
coach battery when you are connected to shore power, or when you run the generator. It will
not charge the
engine start battery unless the boost switch is ON. I'm not sure where your battery charger is located, but I would look in all the storage bays. Look on the walls, and on the ceilings, of all the bays. You'll recognize it by the two big battery cables ( + and - ) that are attached, and it should be plugged into a wall socket. If you find it, check the power cord to see if it is getting 115V power. There might be a circuit breaker on the charger - check that. Your wiring diagram shows the big positive cable from the charger goes through a 80(?) amp breaker on the way to the coach battery. You'll need to find the breaker, and see if it is popped. It may be a auto reset breaker, or it may be manual reset.
2. Don't worry about the shutoff switch next to the door (it's called the "salesman switch" on this Forum) right now. Get the other stuff lined out and then you can work on figuring out the wiring on the switch.
3. Yes - the batteries should be isolated from each other. This is the function of the battery isolator. It allows the alternator to charge both batteries when engine is running, but keeps the batteries separated when the engine is not running. It is possible the isolator has been removed, or replaced with some other device, or is improperly wired, or is malfunctioning. Anything is possible with these old coaches. If you can find the isolator, we can tell you how to do a simple test to see if it is working properly.
Thanks for the quick reply! With that description on the charger, I think I might know where it is. I'll also get searching for the isolator. It might be a couple days for me to get back with the results since I don't have a ton of spare time but I will follow up with what I find.
Thank you.
Jeremy
Possible locations for isolator: on the engine compartment walls, or under the coach behind the driver side rear wheels, or perhaps inside the coach, in the open space at the foot of the bed (lift the mattress platform up to access this space).
Typical 3-post isolator shown below. Yours will be a lot older - may be red instead of blue,
If the boost solenoid is left on or is stuck in the closed position then both batteries would be tied together.
The left side battery should be the engine start bat. The cables point that way. On my coach , I also have a start bat in the driver side last compartment. Take a peek in there . My charger is above the tank dumps. My isolator is on the bulkhead , DS, near the starter .
You might have a 12v converter/charger, mine was on the celing in the water bay. After I changed it my battery lasted 5 years. You may want to consider an AGM house battery.
The solinoid in the center of the picture caused me many issues until I replaced, others have said... could be stuck on combining both batteries, like mine was.
I think your stuck with the 8D, rather than 6v because of the space, house battery. I added another 12v battery next to the engine battery.
I believe the right battery is your start battery, or it should be.
You are correct the salesman switch should shut off all 12v but the frige and c02 detector.
clean your batteries /dirt on the battery cases will drain them a little at a time
hope you find your charger.
larry
On our 93 the stock converter was located behind the entry steps and plugged into a 20 amp outlet there. Here's a photo. The black wood is the back of the entry steps.
jor
In our 91 GV with a 3208T CAT, the charger is located on the ceiling of the sewage dump compartment. The isolator is located in the engine compartment on the lower right side (rear radiator ) The engine battery is located in the compartment under the passenger side (most forward one on pass. side) Our house batteries are under the entry steps which consists of 4 golf cart batteries in a series/parallel configuration. The boost solenoid is also in that space. Have a great day ---- Fritz
OOOPS ---- Our engine battery is in the last compartment aft on the drivers side. (got turned around!!) Have a great day ---- Fritz
If you have the Progressive Dynamics 9100 series, without the optional, still available, charge wizard, all your batteries see is 13.2 VDC which is just enough voltage to keep your batteries from self discharging. One of the first things I did when we started living in our '92 U225 GV was add the Charge Wizard and confirm the output voltage of our PD 9160.
Charge Wizard PD9105 RV Battery Chargers (https://www.progressivedyn.com/rv/charge-wizard/pd9105-tcms-charge-wizard/)
The simplest, cheapest way to keep track of your battery state of charge is an inexpensive (cheap) Chinese LED voltmeter. 12.0 VDC resting equals 50% state of charge. It will also tell you when your 3-stage charger is on bulk (14.6), normal (13.6), and float or storage (13.2).
LED 12V ~ 24V Digital Display Voltmeter Car Motorcycle Voltage Gauge Panel... (https://www.ebay.com/itm/LED-12V-24V-Digital-Display-Voltmeter-Car-Motorcycle-Voltage-Gauge-Panel-Meter/382639948497?hash=item59171e42d1:m:m5ZJitUjucFfhiDO1P9h_9A)
OOps again, I must be sleep typing!! Ours is a side radiator, with rear access. Just returned from a week away, Just foggy I guess!! ---- Have a great day ---- Fritz
My 89 came home with 7 batteries and a dead isolator and abandoned converter in the wet bay. Side radiator model and the engine start battery in the vented port side compartment just aft of the rear wheels make perfect sense adjacent to the starter. Mine had a set of house batteries there. May move start battery from under the steps back to that location to shorten starter cable run. That would consolidate my house batteries to the starboard side. There was also a battery rack in the starboard side air cleaner compartment that contained two dead Costco/interstate group 14 rv house batteries from the summer of 2014. New hybrid inverter will reside on the starboard side within 5 feet of house battery bank and 120 volt panel feeds.
I ordered that coach new with 2 house batteries in the step and the engine start inside the grille.
Great to see the electrical diagram!!! My books didn't have that one, seems very similar for the 86 Grand Villa I have.
My setup is similar to what fkjohns6083 described. My challenge is cable organization, a great deal of large cables are packed into the battery bay and are not very manageable.
Has anyone upgraded their cables or reorganized them?
Bob ---- My cables in the house battery comp't are complex, but well organized. It all came that way to me, I didn't do anything to them, but I can send you a pic. if that would be of use to you. ---- Have a great day ---- Fritz
Ok. Yes, the charger is in the tank dump area. I certainly have seen it there, and knew that it wasn't plugged in, but had no idea it was the battery charger. You can see in the pick that the outlet isn't attached to the ceiling any longer...that may be why he unplugged it so it wasn't dangling down. (pic) Not sure how i'm going to re-attach the outlet to be secure yet but first things first.
I found the isolator located way in the back, on the frame just in front of the back bumper. (pic)
I found a youtube video that shows how to test the isolator so I removed the wires and set my multi-meter to the little arrow thingy on the ohm scale. Between the center post and the left one it seems to operate correctly.....current flowing with the positive lead on the center post but when i reverse it there's no flow. Between the center and right posts however, it just beeps at me with either lead on either post. I assume that means that the isolator is bad. With the isolator having a bad side, would that result in the batteries being drained together? Please advise. Also I would appreciate advice on what isolator would be recommended as inexpensively as possible.
I ran a cord and plugged in the charger as well. It hums and the cooling fan spins, so I figured that was good news. I have the positive leads removed from the batteries so they don't drain right now and put my volt meter on the cables with the charger on. The house battery cables were getting 13.48 volts. The engine start battery cables are getting nothing. So i'm thinking that the side of the isolator that was beeping at me must be the engine bat side??
That's what I've found thus far.
The isolator test you did checks the diodes. It may or may not be valid, depending on your multimeter's capability and quality.
How To Test Diodes | Fluke (https://www.fluke.com/en-us/learn/best-practices/test-tools-basics/digital-multimeters/how-to-test-diodes-using-a-digital-multimeter)
For a more practical "functional test" of the isolator, go to this post by Brett Wolfe:
best way to find a faulty regulator or isolator (https://www.foreforums.com/index.php?topic=20216.msg146180#msg146180)
If this test indicates that the isolator is faulty then "Yes", this might explain why both batteries were being drained.
If, after testing, you decide to replace the isolator you need to get one with the same (or higher) amp rating and 3 posts. Do a Google search and you will find lots of choices. Victron is a well respected brand, but there are others. Search this Forum for the topic "battery isolator" and see many suggestions. (Set the search order for "most recent topics first" to get the latest replies)
With charger plugged in, you are getting charging voltage at the house battery, and nothing at the start battery. This is how it should be. Turn on the "boost" switch on your dash, and (if the boost solenoid is working properly) you should see charging voltage at both batteries.
PS: While you are working on various parts of the electrical system, take every opportunity that comes along to remove, clean up, and reinstall the wires, cables and connections. Dirty/corroded connections are a very common cause of electrical problems.
Thank you. I'll report back what I find....probably tomorrow night.
Good evening. I think I've run the tests as they were pointed out. See pic for details.
The Isolator is a Powerline PLI-130-2
The alternator is rated at 105 amps.
I also took the time to clean up the connections on the isolator.
Your resting voltage on both batteries shows them about 50% discharged. See chart below.
The engine OFF readings on the isolator are not encouraging. You have higher voltage on the center (ALT) post than on either of the outside posts. Voltage on the center post (when alternator is not charging) is usually taken as a sign that one or both of the diodes have failed and are allowing voltage to flow "backwards". How that voltage could be higher than either outer post is a bit of a mystery. The outside post with 11.6 volts does not match either of the batteries. I suspect that cable has a poor connection to whichever battery it feeds.
With the engine running, the voltage on the center (ALT) post looks OK, and the voltage on the left post (13.87) shows about a 0.7 volt drop which looks about right. The voltage on the right post (14.38) is too high, so we might suspect the failed diode is on that side.
I'm thinking a new isolator would be a good investment, but don't do anything hasty until Brett Wolfe and some of the real experts on this Forum chime in. Compared to them, I'm still a amateur at this stuff.
Ok. I'll hang tight a bit. I sure appreciate the support this forum gives!
Fritz,
Yes plz! That would be of help... and thank you Regards Bob
I have chatted with a couple other Forum members about your test results. We are concerned that the voltage readings you got are not logical. If you check the voltage at each battery, and then check the battery posts at the isolator, you should get almost exactly the same reading. If you do not, then there must be a reason. In most cases it will be a poor cable connection - either a loose or corroded cable end and terminal, or a cable which is corroded internally. To accurately test your isolator, you first need to find the cause of your inconsistent voltage readings.
I would recommend checking and cleaning all the battery cable connections, including (very important) both ends of any ground cables. A good solid ground connection is essential to a proper electrical circuit. When cleaning the cable ends, be sure they are tightly attached to the cables, and that there is not any heavy corrosion showing on the wires where they go up into the insulation.
While you are cleaning the battery connections, take the opportunity to identify which battery is connected to which post on the isolator. Remove the cable from one of the batteries, and then check the isolator to see which of the outside posts has zero voltage. Knowing which isolator post goes to which battery may help in your troubleshooting process.
After everything is cleaned up, do your voltage checks again. With engine OFF, the voltage at the batteries must be very close to the same as the voltage at the isolator battery posts. If you can't get to that condition, you will need to figure out why.
If the engine OFF numbers look good, then redo the engine running check at the isolator.
Keep working on it. Chasing down battery system problems is not fun, and is usually dirty work, but it is worth the effort.
Ok. I'll work on it over the next few days and report back when I have logical reading. Thank you.
I had some time to tinker with it today. I pulled the cables off the isolator and tested them for the voltage and they matched up with the reading directly on the batts so obviously I didn't get the terminals cleaned well enough last time. I removed the isolator so I could get to it with a wire brush on a drill and got them cleaned up good. I noticed that the resin or epoxy that they use to seal the top of the isolator has a spot that has lifted between the left and center terminals. (see pic) I don't know if that's indicative of it getting too hot or if it's just because it's almost 30 years old. But I thought it was worth mentioning.
Attached is a pic of the readings now. Yes, the batteries are a bit more run down at the moment. Hopefully that doesn't affect the results of what we are trying to figure out.
Jeremy
If it were me, I'd change that out.
Jeremy,
Those readings on the isolator battery posts (before engine start) look a lot better this time. Good work!
You are still showing voltage on the center post with engine off. That is one potential strike against the isolator.
With engine running, the center post (ALT) voltage looks OK. The house battery post is down 1.3 volts, which is more of a drop than we would like to see. The start battery post is only down 0.2 volts, which is much less of a drop than normally expected. These two results are the second strike against the old isolator.
And strike number 3 is the physical condition. Isolator looks pretty rough, and the lifted potting material is not a comforting sign.
Personally, I would add a second vote for a new isolator.
OR, investigate the possible alternatives to a diode based isolator. Several threads on the Forum about that subject. For instance:
Schottky based isolator vs combiner (https://www.foreforums.com/index.php?topic=31468)
New battery isolator (https://www.foreforums.com/index.php?topic=31174)
Battery Isolator (https://www.foreforums.com/index.php?topic=30077)
I am quite happy with my cole hersche smart isolator
Foretravel Tech Talk (https://www.foreforums.com/index.php?board=5.0)
All new coaches come with combiners
Thanks, all for your input. I'll decide what to replace the old isolator with and see if that clears up the issues that I'm experiencing. Might be a week or two but I'll report back my findings.
Well I guess it's time to report back what I have done with this thing. I started researching isolators and combiners and I gotta say that my head started spinning rather quickly. It isn't the most exciting reading material out there!
I decided to go with a Victron Cyrix-ct Intelligent Battery Combiner for a couple reasons. It was inexpensive (I think it was $42 on Amazon) and the installation seemed easy enough for me to handle...which is important since electronic stuff isn't my strong suit.
I decided to go with 2 12V golf cart batteries for the coach which I purchased at Batteries Plus for just over $100 ea. I had to rout out the plywood base that I put in the battery compartment a bit so they would fit under the stairs. It was close but I made it!
I took Old Toolmaker's advice and bought a couple of the cheap 12V LED Voltmeters and built a panel in the compartment next to the stairs as you walk in. Then I printed the Battery SOC Chart that Chuck sent on some industrial label material so that all of the information is right there and understandable at a glance for a dummy like me, and I don't have to open up the stairs to see the condition of the batts, which I love. In all, I probably spent around $275 for everything.
I haven't truly tested things out on a trip yet, but it appears that I've accomplished what I set out to do. I want better performance from the house batts which I think will be obvious when we really start using it. I needed to get the batteries isolated so both wouldn't drain down. The Victron is doing its job. I wanted the salesman switch to work properly and once I had everything connected properly, it worked just fine.
I reattached the outlet that was hanging in the tank dump bay so I could plug the charger back in. It seems to be doing its job now in charging the coach batt. Running the engine with the alternator charging will charge the engine start battery until it hits a certain voltage and then will also charge the coach battery. (I think that's why it's called a combiner!) It was hard for me to get everything mounted straight and pretty because that combiner is pretty small and those 4GA cables are huge and not very flexible.
From here, I don't know if there should be further testing that should be done but in my eyes, things seem to be working properly, which they haven't been since 'Stretch' has been in the family. But please feel free to correct me if you think something else should be done.
I truly appreciate knowledge that you-all are willing to share. It's been an overdue learning for me and your advice made it a whole lot easier. Thank you.
So much red
Congrats! I'd say you did a great job of straightening out your battery compartment, and getting control of your charging system. Well done!
The Cyrix-ct looks like a great combiner. Since it is bidirectional, it should also keep both battery sets charged when on shore power.
https://www.victronenergy.com/upload/documents/Datasheet-Cyrix-ct-120A-230A-EN.pdf
Only thing I might add is a way of watching the voltage of both battery sets while driving the coach. I don't know what you have on your dash for volt meters. If there is one in your instrument panel, it probably shows chassis (start) battery voltage. Easy to tell - watch the gauge and turn on your headlights. If voltage drops, it is showing start battery voltage.
To monitor the coach battery from driver seat, if you have a lighter socket on the dash, it might be connected to the coach battery. If so, you can utilize a inexpensive "lighter plug" volt meter. If no lighter socket, then another small surface mount volt meter can be stuck on the dash. Photo below of two volt meters and lighter plug meter on my dash. Very handy for a quick check of voltages while driving.
Hi Chuck. I do have an in-dash monitor...see pic. I guess this opens up another round of questions. I'm questioning the reliability of the volt meters in the monitor since they aren't even close to the readings from the new ones that I hooked up at the batteries. Perhaps that is indicating connectivity issues to the dash?? You can also see that when the monitor is on, there is a line across the bottom of the display so it doesn't fully show all of the info that it's meant to. When the batts are down, it's even worse. It's the same when I switch it to camera. That's always bugged me but I think I just thought things were getting old.
When you talk about watching the voltage while driving, am I assuming correctly that it is to prevent overcharging? And if so, what can/should be done about it?
Jeremy
When driving you want to know if the battery charging rate (battery voltage) is too high OR too low. Either condition could be the first indication of a problem which requires further investigation. Better to catch such problems early before batteries suffer.
I suspect that the Audit display voltage is incorrect. Check the voltage at your batteries with your multimeter, then see what the Audit display and your new volt meters show. If the Audit display battery voltage is way off, then it is useless.
Figuring out exactly where the Audit display gets its battery voltage reading may be difficult. You MIGHT have a schematic in the owners manual that shows the wiring inputs to the Audit ECU and where they originate. There is a diagram posted in the Forum library for the Audit 760 and 1160 systems, but I think your system is a earlier iteration (Audit 700) since it has fewer display features.
https://www.foreforums.com/index.php?action=media;sa=item;in=3270#viewitem
Many members have replaced the aging Audit displays with newer more accurate and reliable technology. Since doing so will involve coming up with 3 new systems (tank levels, battery voltage, and rear view camera) it might require a lot of reading of pertinant Forum threads on the different subjects before you make any choices.
If you decide to go down that path and have questions, you should start a new thread for each topic.
When I was installing the new volt meters, my multimeter was consistent with them. I'll check it again but it likely won't happen until our camping trip in a couple weeks. I'll keep an eye on the batt levels and will just use the audit display for the tank levels. For now I'm anxious to see how the dual 6-volts perform compared to having to run a small generator with a 100' cord in the bushes all day!
Thanks again for the direction!
Jeremy