LVD Alarm and red indicator light not operating

[chin_k]

Jon:
The two voltages I am looking for is between the alarm post and the Vin, and alarm post to Vout. You gave me three voltage values. I just need the value when the LVD is off (STORE). For fun and giggle, measure the voltage on STORE between the white post (ground) with V-in and V-out. I want to make sure the alarm is working as a ground when it is STORE and when the converter is working.

Going from this, you may need to look at grounding, but I am trying not to give you too many options. We should do trouble shooting slow and meticulously, one step at a time.

[ski2ways]

Jon:
The two voltages I am looking for is between the alarm post and the Vin, and alarm post to Vout. You gave me three voltage values. I just need the value when the LVD is off (STORE). For fun and giggle, measure the voltage on STORE between the white post (ground) with V-in and V-out. I want to make sure the alarm is working as a ground when it is STORE and when the converter is working.

Ok, here's the new measurements, with Gray wire disconnected, LVD on STORE, no shore power and red SENSE wire connected:

alarm post to Vin: 0.00
alarm post to Vout: -0.20

For fun and giggle:
ground to Vin 13.25
ground to Vout 0.00

Do you have an idea how the "Switch to on if lit LED" is supposed to work when shore power is connected and the Coach Batteries switch is OFF? My assumption, under the norm, is that the red LED is illuminated and the green LED is NOT illuminated when shore power is applied. The converter/charger is not charging the batteries unless the switch is set ON. Under the norm, when the switch is pushed on, the red light and alarm are deactivated, and a charge is being applied to the batteries.

In the current, not norm situation, when I apply shore power and the Coach Batteries switch is off, only the green LED illuminates, and I have DC power; my DC appliances work. Further, I do not see a voltage increase to the LVD. When I switch the Coach Batteries to ON, I see an immediate jump in voltage at the V-in terminal. So,the STORE part of the switch is working, but the "Switch to ON if LIT" circuit is not working.

So, here's my take: When the batteries are on STORE and shore power is applied, the converter/charger applies voltage/amps to the LVD via the 8AWG red wire from the brown box to the Vout post of the LVD. And then what? The green wire is hot, it is actually hot all the time, correct? But in the current situation, there is something wrong and the circuit is broken, because the red light and the alarm red wires are connected to the hot green wire at the overhead, and the black wires of BOTH are connected to the gray wire which is connected to the alarm post. There is something wrong at the alarm post in this situation, but not in the situation when I disconnect the SENSE wire, because the alarm sounds when that wire is disconnected and the gray wire is connected.

Long winded discussion, but it appears to me that the alarm post is not working as a ground when shore power is applied and the Coach Batteries switch is on STORE.

Jon

[chin_k]

You should have other symptoms like the following:
1, when you disconnect your battery at the LVD, and plug in your shore power, your DC appliances does not work.

The above is incorrect. I will edit my post to remove that statement. The converter is connected to the DC panel, and so without the batteries, all your DC appliances will work, just not charging your coach batteries. Sorry for the confusion.

Ok, here's the new measurements, with Gray wire disconnected, LVD on STORE, no shore power and red SENSE wire connected:

alarm post to Vin: 0.00
alarm post to Vout: -0.20

For fun and giggle:
ground to Vin 13.25
ground to Vout 0.00

What I was looking for is the measurement when the LVD is on STORE, but shore power is on. Sorry about this, but can you do the measurement for us?

The "STOIL" LED and buzzer works when there is a voltage on the V-out (since it connects to the converter), and the ALARM post is grounded (when the LVD is off, and the set point LED turns on. The electricity flows up the green wire, thru the resettable breaker, thru the buzzer/LED, then back to the LVD via the gray wire, then into the ground, which is connects to the converter ground, completing a circuit.

It is normal for the green LED to be on when you have the converter working, as I corrected myself in the top of this post. This is because the V-out is connected to the ground via the green LED above the driver panel, independent of the switch position (STORE or ON). You see that there is a ground wire from the LED pass the switch to the area labeled "UNDER DASH".

What you said is correct about the gray wire/alarm post. What I want to do is to confirm that it is the issue by asking you to do the measurement with the converter working. I hope that is the last thing that we need to see before we declare your LVD is sane and working.

[ski2ways]

Chin_k,

Not a problem. I'll redo the same set of tests with the shore power on, but the switch on STORE. I'll have to do that tomorrow.

After I do the tests again, I have another Idea. What if I connect the gray wire to ground, i.e., the white wire post, with the switch on STORE and shore power plugged in. I 'm betting the alarm sounds and the red LED illuminates. Your thoughts?

Jon

[chin_k]

If there is power on V-out, whenever the gray wire is grounded, the buzzer will alarm. This will happens when the LVD is ON, or the converter is working. I think no one want to do that to reminds them the DC appliances are usable.

On a proper working LVD, the alarm post will not be grounded when the LVD is ON so that it only will buzz when you have the converter on (shore power or genset is running). The LVD will ground the alarm post when it is STORE (off), or when the SENSE voltage is too low.

[ski2ways]

If there is power on V-out, whenever the gray wire is grounded, the buzzer will alarm. This will happens when the LVD is ON, or the converter is working. I think no one want to do that to reminds them the DC appliances are usable.

On a proper working LVD, the alarm post will not be grounded when the LVD is ON so that it only will buzz when you have the converter on (shore power or genset is running). The LVD will ground the alarm post when it is STORE (off), or when the SENSE voltage is too low.

Chin_k,

I wasn't indicating that I would ground the gray wire to the LVD ground permanently. It was only to provide further proof that the alarm and red LED are not the failure here.

The results of your troubleshooting suggestions will show in my mind that I now do not have a proper working LVD when it comes to alerting me that I must turn the Coach Batteries Switch on so that the batteries can be charged. Hence the need for me to put a yellow ribbon on the 30Amp shore power plug to remind me to turn the switch on after plugging in shore power. I still have to figure out what alert method I will use when I run the generator...

Let's see what tomorrow brings.

Regards,

Jon

[ski2ways]

Chin_k,

The new measurements, Coach Batteries Switch on STORE, shore power applied, gray wire disconnected, SENSE wire connected:

alarm post to Vin: 0.00
alarm post to Vout 0.00

ground to Vin: 13.25
ground to Vout: 13.77

Also, I touched the ground post (white wire) with the gray wire and the alarm sounded, as you told me would happen.

Jon

[chin_k]

OK, you win. I am wrong.

The alarm post should behave like a ground when the LVD is on STORE (off), but your is disconnected, base on what I see in your last set of measurement.

If you don't need the LVD in a hurry, why don't you send yours to me, and put a postage in there ("self-addressed envelop" deal) so that I can send mine to you? This is an even exchange. If you need it in a hurry, I can sent it to you first. We can go from here in the private message.

[ski2ways]

Chin_k,

Thanks to you, I know that my LVD has a failure to apply ground to the alarm post and that is the reason why the alarm and LED do not work when shore power or generator power is applied, so I have to always remember to turn the coach batteries on. I don't have a problem with that.

Your troubleshooting has also shown that the LVD will disconnect and sound an alarm when the voltage drops to 11.8 volts. If that doesn't happen, it was my biggest concern, and the reason behind wanting to buy your LVD. But, we now know the disconnect will work, and I also have a separate reference point about the current voltage state of the batteries, with the Low Battery Alarm I installed.

So, I appreciate the exchange offer, but at this point let's hold off. Some day I will replace the LVD with an approach like you and a lot of the Chinook Forum folks have already done. Besides, you need a working LVD that you might want to send to someone whose LVD does not disconnect.

Thanks again for your help! The Forum is a gold mine of information about the Chinook, and I couldn't do some of the stuff I have done already without the documentation and messaging going back and forth among members regarding fixes and upgrades. I already know that I will have to replace the converter/charger, the refrigerator and a bunch of the other appliances.

Best regards,

Jon

[chin_k]

I learn a bit about the LVD too. For simple trouble shooting, the most helpful thing is that we just have to disconnect the SENSE wire, and do not need to run down the battery or use a potentiometer to reduce the voltage. It think that is the most time saving tidbit.

It will be interesting to know why yours does not ground. It does ground when the SENSE is disconnected. But I guess people like me or red baron (a fellow member here) are those that are curious about this and would investigate and post about it.