Bird testing?

[Greg84]

Because the fun never ends!

So, back in the first week of Aug I had my inverter replaced. Since then all has been well until recently.

We were are at a campground (50 amp) last week and the day we went to move I noticed "brownout" on the Power Control System (PCS). I understand that reflects low voltage at some point. I'm not sure when this happened, probably the night before when we were asleep. I use a Progressive Industries EMS PT50C surge protector that provides an low voltage error message and cycles off when the voltage drops below 104v and cycles back on when the voltage returns. When I plugged in at the campground there where no error msgs.

We left the campground and drove about 4 1/2 hours with the inverter powering the fridge and hot water heater (usually off, forgot to turn it off). When we got to the campground levels wouldn't work...turned out the house batteries where dead and had a low btry indicator fault on the control panel. Plugged into shore power and waited a few minutes and all was well. Jacks worked and the fault was gone and the house batteries were charging.

Today we pulled stakes and hit the road again. House batteries fully charged. About 5 hours into the trip the radio went dead and btry fault indicator again. The house batteries were dead again.

I don't think the "brownout" had anything to do with the dead house batteries but I'm asking.

I'm pretty confident that the alternator is not charging the house batteries with traveling and that the Bi-Directional Isolator Relay Delay (BIRD) may have gone bad.

But before I start throwing parts (and $$$) at the problem I thought I'd test the BIRD. How do I test the BIRD to see if it is working properly?


I tried searching with no luck. My apologies if I missed it and this question has been asked before.

[bevedfelker]

Greg: I attached a file I had that some BIRD troubleshooting hints for the coach batteries not charging and the chassis battery not charging.

The problem might be the isolation relay (often called the Trombetta) shown in the schematic. Here is some troubleshooting tips for the Axis/Vegas Trombetta provided by Oneilkeys on the forum:

"If you have a volt meter, plug into shore power and measure the voltage at the chassis battery. If the system is working correctly, after a few minutes the voltage at the chassis battery should read above 13 volts - it should read the same voltage as the house batteries which are also being charged. Since the chassis battery terminals are not that easy to reach, I find it easier to read the voltage off of the two large terminals of the Trombetta on the right side (driver's side) front of the engine. It is easily accessible with the front grill down. The voltage should be the same at both terminals is both the house and chassis batteries are charging. Put your red wire from the voltage meter on one of the large terminals and the black wire on any silver bolt in the area for a ground. In my Axis the left hand Trombetta terminal (looking at it from the front) is connected to the house batteries and the right hand one is connected to the chassis batteries. If you search Trombetta and BIRD in this forum you will learn more than you want to learn about this subject as well as how I fixed mine."

[Oneilkeys]

What Charges the House & Chassis Batteries When - Page 4 - Thor Forums

If you read this thread staring back a few pages, it gives you a lot of information on the BIRD/Trombetta issue and how to test I've your's is bad.

Basically the best way to test if the BIRD is opening the Trombetta to allow the alternator to charge the house batteries is either to put a volt meter on the house batteries with the engine running and see if you have above 13.1 v. If you are not, then you may have either a BIRD or Trombetta problem. A second (and easier way) is to test the voltages at the two large posts if the Trombetta. With the engine on or on shore power, they both should read the same. If they both read the same on shore power but not on alternator then there is probably an issue with the BIRD. There are four wires coming out of the BIRD. Two of them are hooked to the house and chassis batteries and when they sense the primary battery being charged (the chassis battery on the alternator and the house batteries on shore power/generator) at above 12.8v the BIRD opens the Trombetta to allow the other battery to charge. There is a small fuse on the wire coming out of the BIRD leading to the chassis battery. You might look at that and see if your power issue blew that fuse. It also could be your problem.

[Greg84]

Ed & OneilKys - Thanks for the responses.

I'll be testing this morning.

[Greg84]

So I did the testing this morning.

Voltage at the Trambotta with the engine running:

House Batteries - 11.8
Chassis Batteries - 14.0

I also called Thor, they said you can check the BIRD by measuring the purple wire (to Relay Coil). The voltage is supposed to be 13.2. Mine measured 12.1.

So yep, the BIRD is bad. Now to replace it.

Thanks for the help Gents. Greatly appreciate it.

[Oneilkeys]

Just for curiosity, did you check the voltages on shore power or generator? If the BIRD is really sick I would expect similar voltages only backwards.
Checking the voltage at the coil is good to know. In all my discussions with the BIRD rep, that was never mentioned.
It is also interesting for your book Ed, that the BIRD manufacturer has changed the color of the wires (in an apparent effort to confuse us even more - as if we were not confused enough already). As you can see from the attached photo, the wire going to the coil from my BIRD is white - not purple.

[blw2]

maybe I'm taking a backwards step here....
but isn't this device designed to charge the house battery bank with the chassis alternator.... BUT only IF the chassis battery is good to go?

If that is the case, just because you're not seeing charge voltage at the house battery i wouldn't automatically assume the thing is dead. Maybe it's trying to charge up the chassis battery before it charges the house.....

[Greg84]

Originally Posted by Oneilkeys

Just for curiosity, did you check the voltages on shore power or generator? If the BIRD is really sick I would expect similar voltages only backwards.

Didn't check when the generator was running. But I did check with shore power only.

With shore power:
Chassis Battery: 13.2
House Battery: 14.4

Note: I couldn't actually trace the wiring from the trambotta to the batteries because both wires went behind paneling, but at the same time I took the measurements above I also measured the batteries. Voltage was similar for the trambotta posts as the batteries (+/- 0.2 volts).

I’m not tracking on why you would expect to see reverse voltage when the engine is running?

Would measurements for the house battery of 11.8v signify that there is no electricity being feed into the batteries from the alternator?

Originally Posted by Oneilkeys

Checking the voltage at the coil is good to know. In all my discussions with the BIRD rep, that was never mentioned.
It is also interesting for your book Ed, that the BIRD manufacturer has changed the color of the wires (in an apparent effort to confuse us even more - as if we were not confused enough already). As you can see from the attached photo, the wire going to the coil from my BIRD is white - not purple.

I think our BIRDs may different, I've also got a different model MH, so that may explain the difference. I've attached a picture of mine. The purple wire is supposed to measure 13.2 when the engine is running, mine is at 12.1. When I measured the voltage on the purple wire I waited about 3 minutes after starting the coach to measure.

[camperguy99]

Doubt the BIRD is bad? When you disconnect the purple wire you should hear the Trombetta relay open or close with a loud "clank." With a voltmeter connected between the large terminals of the Trombetta you should see the voltage change from a volt or so to a few tens of millivolts (0.010.) The Trombetta is junk as far as I can tell. Mine closed with a noticable clunk but the contacts stayed open yielding the function of connecting the two battery banks together void. I replaced mine with a White Rodgers 15V coil. About same money but far lower coil dissipation.

[Oneilkeys]

Originally Posted by Greg84

Didn't check when the generator was running. But I did check with shore power only.

With shore power:
Chassis Battery: 13.2
House Battery: 14.4

Note: I couldn't actually trace the wiring from the trambotta to the batteries because both wires went behind paneling, but at the same time I took the measurements above I also measured the batteries. Voltage was similar for the trambotta posts as the batteries (+/- 0.2 volts).

I’m not tracking on why you would expect to see reverse voltage when the engine is running?

Would measurements for the house battery of 11.8v signify that there is no electricity being feed into the batteries from the alternator?



I think our BIRDs may different, I've also got a different model MH, so that may explain the difference. I've attached a picture of mine. The purple wire is supposed to measure 13.2 when the engine is running, mine is at 12.1. When I measured the voltage on the purple wire I waited about 3 minutes after starting the coach to measure.

You were (are) having an issue with the alternator charging your house batteries. If the BIRD and Trombetta are working correctly, after you turn on you engine, the alternator charges only the chassis battery. When the voltage of the chassis battery gets above 12.8v for one minute, the BIRD senses that and opens the Trombetta to allow both banks to charge. It does that by sending voltage thru your purple wire to the Trombetta. Either that is not happening or the Trombetta is receiving the voltage but is not opening.
I asked if you had checked the voltages of the batteries while hooked up to shore power because if the BIRD works in that direction then the Trombetta is working. If you waited for the house batteries to charge above 13.1v, from the voltages you recorded while under shore power the Trombetta is not opening that way either. This means that you cannot rule out the Trombetta as the problem. However, If the BIRD is supposed to put out 13.2v to the Trombetta continuously and yours is only putting out 12.2v, then the BIRD is probably bad.
While your BIRD may be a different version, it looks like the same or a very similar model to the one in my 2016 Axis.

[Greg84]

Originally Posted by Oneilkeys

You were (are) having an issue with the alternator charging your house batteries. If the BIRD and Trombetta are working correctly, after you turn on you engine, the alternator charges only the chassis battery. When the voltage of the chassis battery gets above 12.8v for one minute, the BIRD senses that and opens the Trombetta to allow both banks to charge. It does that by sending voltage thru your purple wire to the Trombetta. Either that is not happening or the Trombetta is receiving the voltage but is not opening.
I asked if you had checked the voltages of the batteries while hooked up to shore power because if the BIRD works in that direction then the Trombetta is working. If you waited for the house batteries to charge above 13.1v, from the voltages you recorded while under shore power the Trombetta is not opening that way either. This means that you cannot rule out the Trombetta as the problem. However, If the BIRD is supposed to put out 13.2v to the Trombetta continuously and yours is only putting out 12.2v, then the BIRD is probably bad.
While your BIRD may be a different version, it looks like the same or a very similar model to the one in my 2016 Axis.

Thanks Oneilkeys. I took additional voltage readings today to verify what I posted earlier. I also took readings when the generator was running:

Shore
Chassis 12.72
House 12.12
BIRD to 12.2
Relay (purple wire)



Alternator
Chassis 14.13
House: 12.59
BIRD to Relay (purple wire): 12.4


Generator

Chassis: 12.8
House: 14.38
BIRD to Relay (purple wire): 13.14

The shore power readings were taken after I had been hooked up to shore power for 3 days. Based on this it does not appear if the batteries had been charged from shore power. Am I interpreting this correctly?

When I took the alternator readings the engine had been running for about 10-15 minutes (and additional measurements after a couple of hours of driving). It does not appear if the Trombetta was opening and allowing the house batteries to charge. Based on the output at the BIRD of 12.4 volts (and what Thor stated of needing 13.2 or so volts) the Trombetta was not receiving enough voltage to open to the house batteries.

With the generator running and shore power disconnected the readings reflect that BIRD was outputting 13.14 to have the Trombetta kick over to the house batteries and begin charging them with 14.38v.



I did check the water level in the batteries and it was ok. Dashboard alternator reading all day today while driving was 13.1. It appears the alternator is ok.

A couple of questions:
1. Am I interpreting the readings correctly?
2. Why would the BIRD relay output work with the generator and not the alternator? Does this signify a potentially larger problem than a bad BIRD or Trombetta?

Thanks for your help.

[camperguy99]

No, I don't think you are analyzing the data correctly. In every case the Bird was feeding the Trombetta with >12V, enough to actuate the relay. In every case you had from 0.6V to 1.5V across the should be closed Trombetta contacts. Your Trombetta is toast. Been there done that!

[Oneilkeys]

If the BIRD and Trombetta are operating correctly, the voltages on the house batteries and Chassis batteries should read the same whether you are running the engine (alternator) or you are on shore power or the generator.

From the voltages you are reading:

Shore power - nothing is charging. This is not a Trombetta/BIRD problem.
Generator - The house battery is charging but the chassis battery is not. This could be a BIRD/Trombetta problem but (to be honest) I do not understand how the house batteries are being charged while on the generator but not on shore power? If the 100 amp breaker at the left hand corner of your house battery box is closed (and I think it must be because the house batteries are being charged under generator) then my best guess is the transfer switch. Again, I do not fully understand the workings of the transfer switch. Maybe someone else can explain how the transfer switch works and if it is possible for it to work while on generator but not on shore power. You do not need the Trombetta to close to charge the house batteries while on shore power or generator. On shore power or generator the Trombetta must close to charge the chassis battery. The opposite under the alternator.
Finally, on the alternator, the chassis battery is charging, but the house batteries are not. Could be a BIRD or Trombetta problem.

I assume from the voltages, that you hooked into shore power first, then ran the generator for a bit and then the engine?

I also do not understand why under the generator the BIRD is putting out 13.14v to the Trombetta and the Trombetta is not opening (indicating that the Trombetta is not operating) but that the BIRD is only putting out 12.4v to the Trombetta while the alternator is running? I would check and see if the BIRD is wired correctly and if the Trombetta is working.

It appears to me that you have one problem (possibly with the transfer switch) involving the generator and shore power and another problem either with the way the BIRD is installed or a bad BIRD or Trombetta.

[Oneilkeys]

Originally Posted by camperguy99

No, I don't think you are analyzing the data correctly. In every case the Bird was feeding the Trombetta with >12V, enough to actuate the relay. In every case you had from 0.6V to 1.5V across the should be closed Trombetta contacts. Your Trombetta is toast. Been there done that!

According to the info Greg84 got from Thor, the Trombetta needs 13.2v from the BIRD to open.

[Greg84]

Originally Posted by camperguy99

No, I don't think you are analyzing the data correctly. In every case the Bird was feeding the Trombetta with >12V, enough to actuate the relay. In every case you had from 0.6V to 1.5V across the should be closed Trombetta contacts. Your Trombetta is toast. Been there done that!

Maybe....I'll toss a new Trombetta at it along with a new BIRD. But I'm not sure if these are the root issue. But for an additional $50 I'll give it a shot.

[Greg84]

Originally Posted by Oneilkeys

According to the info Greg84 got from Thor, the Trombetta needs 13.2v from the BIRD to open.

Yeah, I just went back and reviewed my notes from talking with them. I'm going to call them again tomorrow and walk through the whole issue again. I'll post up results of the conversation.

Have I mentioned how much I hate electricity?

[Oneilkeys]

While I agree that the Trombetta may be bad, even if you replace it it will not close if it is not receiving the correct voltage from the BIRD under all three inputs. It also will not solve the problem of the house batteries not charging under shore power.

[Greg84]

Originally Posted by Oneilkeys

If the BIRD and Trombetta are operating correctly, the voltages on the house batteries and Chassis batteries should read the same whether you are running the engine (alternator) or you are on shore power or the generator.

From the voltages you are reading:

Shore power - nothing is charging. This is not a Trombetta/BIRD problem..

Hmmmm.....just went out and measured while on shore power...house batteries are now showing 13.3....so it looks like they are charging. Wonder if the batteries are not holding a full charge charge.

Originally Posted by Oneilkeys

Generator - The house battery is charging but the chassis battery is not. This could be a BIRD/Trombetta problem but (to be honest) I do not understand how the house batteries are being charged while on the generator but not on shore power? If the 100 amp breaker at the left hand corner of your house battery box is closed (and I think it must be because the house batteries are being charged under generator) then my best guess is the transfer switch. Again, I do not fully understand the workings of the transfer switch. Maybe someone else can explain how the transfer switch works and if it is possible for it to work while on generator but not on shore power. You do not need the Trombetta to close to charge the house batteries while on shore power or generator. On shore power or generator the Trombetta must close to charge the chassis battery. The opposite under the alternator.

Exactly what I was wondering. Kind of an odd situation....doesn't make sense. But as I mention above they appear to be charging now. With regard to the 100 amp breaker, I did test it before we moved today and reset it. But it didn't appear to impact the alternator charging.

Originally Posted by Oneilkeys

Finally, on the alternator, the chassis battery is charging, but the house batteries are not. Could be a BIRD or Trombetta problem.

I assume from the voltages, that you hooked into shore power first, then ran the generator for a bit and then the engine?

Not quite. We moved today, before I started the engine I took the shore power readings. Before we traveled and after running the engine for 15 minutes or so) I took the alternator readings. Took the same readings after about 2 hours of travel. More or less the same - chassis at 13.96v, house at 12.2. The house batteries had not charged.


Ran the generator at the new campground and took readings at that point.

Originally Posted by Oneilkeys

I also do not understand why under the generator the BIRD is putting out 13.14v to the Trombetta and the Trombetta is not opening (indicating that the Trombetta is not operating) but that the BIRD is only putting out 12.4v to the Trombetta while the alternator is running? I would check and see if the BIRD is wired correctly and if the Trombetta is working.

As I mentioned earlier we had the inverter replaced the first week in Aug. I'm wondering if something wasn't installed correctly at that time. But for over a month and several thousand miles I had no problems. So that doesn't seem likely.

Originally Posted by Oneilkeys

It appears to me that you have one problem (possibly with the transfer switch) involving the generator and shore power and another problem either with the way the BIRD is installed or a bad BIRD or Trombetta.

A bad transfer switch may be the problem. I bough an extended warranty when I purchased the MH. If replacing the BIRD and Trombetta don't resolve the issue, I'll take it in when we return home in 12 days. I may just have to run the generator when driving.

Thanks for the help and the patience.

[Oneilkeys]

It's really a complex issue - especially when you throw 12v into the mix and three different charging systems. It took me over two weeks of talking to Thor, the BIRD people and the Trombetta rep before I figured out that Thor had wired my BIRD incorrectly. Even then it took a guy on another RV forum to help me find the courage to cut one off the wires and rerout it. Good luck. I know how frustrating it can be. if your house batteries are really charging on both shore power and generator, then it probably narrows down your problem to the BIRD and/or Trombetta. On mine, the red wire that was supposed to go to the house batteries was hooked up to somewhere?? But not to the house batteries. When I cut the red wire and routed it directly to the Tronbetta, all my problems went away. One mistake at the factory can cause a world of hurt. If your system worked once and now does not, that certainly raises the odds that something (like the BIRD and /or the Trombetta) went bad.

[S.Hinman]

One more place to check. With the engine running, check the yellow wire connected to the "Ignition" terminal (BIRD). It should be about the same voltage as the chassis battery. If it is 0V, check the fuse in the front compartment (under the driver's seat).

To check the Trombeta solenoid. Start the engine, the chassis battery should be ~14V. You already measured the coach batteries at 12.59V. Push and hold the "Aux Start" dash switch and recheck the coach batteries. If it is the same as the chassis battery (14V), the solenoid is working.