What Charges the House & Chassis Batteries When

[Oneilkeys]

Originally Posted by rvschneider

Hi all. New to the forum. I've been trying to educate myself on the RV electrical system. This is thread is great, but I still have questions. Problem: My chassis battery was dead the other day, even though I had it plugged in to shore power; Use switch was ON. (Coach battery was fine)

So today I went to the RV and located the Isolator relay under the hood. Took some voltage readings in an attempt to isolate the problem (no pun intended ). Sorry for the long post but here's everything I measured:

1. Engine OFF. Not Plugged in to shore power. 'Use' switch ON. House battery 13.0V. Truck battery 13.0V. Isolator relay not engaged. This is just my baseline so yes I know this step is unnecessary.

2. Engine OFF. Not Plugged in to shore power. Use switch OFF. House battery 13.2v. Truck battery 13.0v . Isolator relay not engaged.

3. Engine OFF. Plugged in to shore power. Use switch ON. House battery 14.0v. Truck battery 13.0v. Isolator relay not engaged.

4. Engine OFF. Plugged in to shore power. Use switch OFF. House battery 13.0v Truck battery 13.0v. Isolator relay not engaged.

---- Started the engine----

5. Engine Running. Not plugged in to shore power. Use switch ON. House battery 15.0v. Truck battery 15.0v. Isolator relay engaged (energized and equal readings on both large posts).

6. Engine Running. Not plugged in to shore power. Use switch OFF. House battery 15.0 . Truck battery 15.0V. Isolator relay engaged

7. Engine Running. Plugged in to shore power. Use switch ON. House battery 15.0V. Truck battery 15.0V. Isolator relay engaged

8. Engine Running. Plugged in to shore power. Use switch OFF. House battery 15.0V. Truck battery 15.0V. Isolator relay engaged

-----

Since the Isolator relay actually does function and allows charging from Chassis --> Coach (but not the other direction) my guess is this is a bad BIRD?

Thanks!
_______________________
2014 Thor Four Winds 32'

Everything seems to be working correctly while under engine power and the Trombetta (pic #1) is opening and closing correctly while the engine is running. Everything on the coach side seems to be working as it should except for #3 where the Trombetta is not opening when the coach is on shore power or generator. Since everything else seems to be working correctly and the Trombetta is working while the engine is running, the problem probably is with the BIRD or BCC. If you have a BIRD, it says BIRD on it and there are four wires coming off it. That red wire coming off the Trombetta in pic #1 that has a fuse holder attached to it should lead back to the BIRD. In my coach the red wire from the BIRD is hooked to the coach batteries. If u back up a take a wider view picture, I might be able to see the BIRD and the wires. Have you checked the fuse holders attached to the wires that run from the Trombetta? If the 5amp fuse is blown, the BIRD cannot sense the voltage at the coach batteries, so it will not open the Trombetta to recharge the chassis battery.

[rvschneider]

Thanks, I'm going back out tomorrow so I'll take another look. I'm pretty sure there wasn't another relay box anywhere in the engine compartment, at least not when looking from above. I checked one of the fuse holders and it was fine but forgot to check the other (got in a hurry) so I'll do that tomorrow. Not sure what a BCC is, but I just assumed that since the RV has an AUX start switch in the cab that it should also have a BIRD, but I'm just going off of what I read online...

[JamieGeek]

Originally Posted by rvschneider

Thanks, I'm going back out tomorrow so I'll take another look. I'm pretty sure there wasn't another relay box anywhere in the engine compartment, at least not when looking from above. I checked one of the fuse holders and it was fine but forgot to check the other (got in a hurry) so I'll do that tomorrow. Not sure what a BCC is, but I just assumed that since the RV has an AUX start switch in the cab that it should also have a BIRD, but I'm just going off of what I read online...

Our Axis has a BCC and the emergency start switch.

[Oneilkeys]

Originally Posted by rvschneider

Thanks, I'm going back out tomorrow so I'll take another look. I'm pretty sure there wasn't another relay box anywhere in the engine compartment, at least not when looking from above. I checked one of the fuse holders and it was fine but forgot to check the other (got in a hurry) so I'll do that tomorrow. Not sure what a BCC is, but I just assumed that since the RV has an AUX start switch in the cab that it should also have a BIRD, but I'm just going off of what I read online...

Your Four Winds is over 2 years old so it either has a BIRD or Battery Control Center (BCC) which perform the same function. If your system worked and now does not, then it was installed correctly. Both BIRDs and Trombettas have been reported as bad in this forum, so it could be either, if the fuses and wiring are OK. Since it seems to work from the alternator to the Coach batteries this lessens but didn’t not eliminate the chance that it is the Trombetta. I would look at the fuses, the wiring and check the BIRD first. Good luck. These electrical problems can be very frustrating. It took me two weeks to figure out that Thor had miswired the BIRD at the factory.

[Oneilkeys]

Originally Posted by rvschneider

Also, the BIRD that is on my truck doesn't look like the other ones I've seen on this thread. If I need/want to replace it, can I replace it with a newer one? The RV has an Aux Start switch in the cab, but it has never worked since I've owned it (2 years).

_______________________
2014 Thor Four Winds 32'

If I have to replace my BIRD and/or Trombetta, I will put in a BIM 160. It is a BIRD and Trombetta in one unit. About $200.

[rvschneider]

Thanks guys. Went out to the camper today and thought I had solved the mystery. One of the two red fuse holders didn't have a fuse in it. Thinking I had figured it all out, I put in a new 7.5A fuse, and...nothing. Still the same result. But I did find a part number on the BIRD, or whatever it's called. It's an Intellitec 00629-120 isolator relay. I'm wondering if the Aux Start switch is part of the problem. It is connected to the same terminal on the isolator relay as the red wire from the BIRD.

I like the idea of the BIM 160, so I may look into it as oppose to buying another one of these relays.

[Oneilkeys]

You said that the emergency start switch had not worked in the two years you have owned the coach. Has the charging system worked for the last two years?

[Jeff H]

Originally Posted by Oneilkeys

If I have to replace my BIRD and/or Trombetta, I will put in a BIM 160. It is a BIRD and Trombetta in one unit. About $200.

For Oneilkeys, and others if interested.

I have the BIM 160. After intensive research of about 2 hours, I've determined that I don't have the BIRD or the Trombetta, and I am still unsure exactly where the isolation relay is though.

I keyed in on your 100 amp breaker and connection statements, and I found 2 connections loose, both on the breaker. My measurements during my exam of the coach batts lead me to find the loose connections. I'm charging the coach batts via shore power over night. But Voltages on the Batts read 12.13, so I'm not sure I'm doing any good waiting.

Now, with that said, I pray the voltages were just too low and the BIM couldn't manage the charge to the Coach batts until the connections have been tightened.

I also found a 50 amp breaker next to my Coach 100 amp breaker. Unsure how to test this 50 amp breaker, as I see it only has a yellow flag, but no means of testing it. I put my meter on it and couldn't get any reading on it. Anyone know what this breaker does? I ran out of day light, so tomorrow is my opportunity to determine what it does. See attachment

[16ACE27]

Originally Posted by Jeff H

For Oneilkeys, and others if interested.

I have the BIM 160. After intensive research of about 2 hours, I've determined that I don't have the BIRD or the Trombetta, and I am still unsure exactly where the isolation relay is though.

I keyed in on your 100 amp breaker and connection statements, and I found 2 connections loose, both on the breaker. My measurements during my exam of the coach batts lead me to find the loose connections. I'm charging the coach batts via shore power over night. But Voltages on the Batts read 12.13, so I'm not sure I'm doing any good waiting.

Now, with that said, I pray the voltages were just too low and the BIM couldn't manage the charge to the Coach batts until the connections have been tightened.

I also found a 50 amp breaker next to my Coach 100 amp breaker. Unsure how to test this 50 amp breaker, as I see it only has a yellow flag, but no means of testing it. I put my meter on it and couldn't get any reading on it. Anyone know what this breaker does? I ran out of day light, so tomorrow is my opportunity to determine what it does. See attachment

Probably goes to your leveling system pump.

[Jeff H]

Picture of 50 Amp Breaker near Coach Batteries

Any ideas how to test this one? Has a yellow flag, but no test button.

[Oneilkeys]

Originally Posted by Jeff H

For Oneilkeys, and others if interested.

I have the BIM 160. After intensive research of about 2 hours, I've determined that I don't have the BIRD or the Trombetta, and I am still unsure exactly where the isolation relay is though.

I keyed in on your 100 amp breaker and connection statements, and I found 2 connections loose, both on the breaker. My measurements during my exam of the coach batts lead me to find the loose connections. I'm charging the coach batts via shore power over night. But Voltages on the Batts read 12.13, so I'm not sure I'm doing any good waiting.

Now, with that said, I pray the voltages were just too low and the BIM couldn't manage the charge to the Coach batts until the connections have been tightened.

I also found a 50 amp breaker next to my Coach 100 amp breaker. Unsure how to test this 50 amp breaker, as I see it only has a yellow flag, but no means of testing it. I put my meter on it and couldn't get any reading on it. Anyone know what this breaker does? I ran out of day light, so tomorrow is my opportunity to determine what it does. See attachment

The BIM has no impact on charging your coach batteries using shore power or the generator. When on shore power the BIM only affects the charging of the chassis battery. If you are plugged in and the coach batteries read less than 13.1v then the converter/charger is not charging the batteries.
1. Is your Use/store in the use mode.
2. Is the breaker in the back of your coach battery box closed.
3. Is there power from shore power thru the transfer switch to to converter/charger.

[Jeff H]

Originally Posted by Oneilkeys

The BIM has no impact on charging your coach batteries using shore power or the generator. When on shore power the BIM only affects the charging of the chassis battery. If you are plugged in and the coach batteries read less than 13.1v then the converter/charger is not charging the batteries.
1. Is your Use/store in the use mode.
2. Is the breaker in the back of your coach battery box closed.
3. Is there power from shore power thru the transfer switch to to converter/charger.

Answers:
1. I can't tell if USE mode works as I see no response when Coach is under engine power.
2. Yes, the 100 Amp breaker is closed and voltage is present at the breaker to the Coach batteries.
3. Yes, I'm very sure the power is present as everything works as required under Shore power.

[Jeff H]

Originally Posted by Tfryman

Probably goes to your leveling system pump.

Tfryman,

I wish I had a leveling system!

[rvschneider]

Originally Posted by Oneilkeys

You said that the emergency start switch had not worked in the two years you have owned the coach. Has the charging system worked for the last two years?

I have not noticed a problem before with the chassis battery being drained, but that may just be due to luck I'm going to clean the terminals on the isolator relay and try it one last time before attempting to replace parts. Might as well replace both BIRD and isolator relay at the same time white I'm at it. BIM 160 looks appealing...

[Oneilkeys]

Originally Posted by Jeff H

Answers:
1. I can't tell if USE mode works as I see no response when Coach is under engine power.
2. Yes, the 100 Amp breaker is closed and voltage is present at the breaker to the Coach batteries.
3. Yes, I'm very sure the power is present as everything works as required under Shore power.

Ref#1 You know if the USE/Store works if, when the coach is unplugged and the engine is not running and the switch is in the USE position, you have 12v power to the coach. If the coach batteries are charged and you have no power to the coach either the USE/Store or the 100 amp breaker in the battery box is open or bad. (As long as the wiring is OK.)
Ref#2, if the 100 amp breaker to the coach batteries is closed and has power to one side but the voltage is not getting to the coach batteries, then that breaker is bad - and that could be your whole problem.

Before you replace the BIRD or Trombetta, I would unplug from shore power and turn on the engine. Then check the voltage on both sides of the Trombetta. Volt meter positive to the engine pole side of the Trombetta and negative to ground. It should read above 13.5v. Now do the same thing to the coach battery side of the Trombetta. If it reads less than the Engine side (12v or so) then the Trombetta is not opening as it should. Either the BiRD or Trombetta are bad or the BIRD is not sensing the voltage of the chassis battery.
If the voltage at the Coach side of the Trombetta is the same as the engine side, then the BIRD/Trombetta are working correctly.

Ref#3.just because everything works in the coach under shore Power does not mean the the USE/Store and/or the 100 amp coach battery breaker are working correctly. The converter/charger is supplying the power to the coach. If on shore power, the voltage on the coach batteries is not above 13.1v then the voltage is not getting from the converter/charger to the batteries thru either the USE/Store or the 100 amp breaker.

So, if you read the same voltage on both sides of the Trombetta with the engine running, the BIRD/Trombetta are good. If that is so and you do not read the same voltage on the coach batteries, either the Use/Store or 100 amp breaker is bad.

Just trying to make sure that you don’t pay $200 for a BIM, when the BIRD/Trombetta are good and either the Use/Store or 100 amp breaker are your real problem.

[rvschneider]

So after further investigation, here's what I figured out. My Thor Four Winds does not have a BIRD. It has an IRD, but not a BIRD. It's an Isolator Relay Delay, so it only works one direction, from Chassis to Coach, not the other way. Even though my owners manual shows a BIRD. I'm disappointed in Thor for not spending the extra $50 to install a BIRD buy my lack of knowledge when purchasing the RV is ultimately to blame.

So, I'm going to install a BIRD (00362-100) and a new isolator relay since the old one is corroded pretty bad.

Also, I tested the Aux start switch after installing the fuse, and it works great. So the IRD is working as advertised, just not the way I want it to ��

[Oneilkeys]

Originally Posted by rvschneider

So after further investigation, here's what I figured out. My Thor Four Winds does not have a BIRD. It has an IRD, but not a BIRD. It's an Isolator Relay Delay, so it only works one direction, from Chassis to Coach, not the other way. Even though my owners manual shows a BIRD. I'm disappointed in Thor for not spending the extra $50 to install a BIRD buy my lack of knowledge when purchasing the RV is ultimately to blame.

So, I'm going to install a BIRD (00362-100) and a new isolator relay since the old one is corroded pretty bad.

Also, I tested the Aux start switch after installing the fuse, and it works great. So the IRD is working as advertised, just not the way I want it to ��

Interesting. Learn something new every day. Didn’t know there was something pre-BIRD. Instead of buying a BIRD and isolator relay, I would consider a BIM 160 which is a BIRD and isolator relay in one unit. Costs about $200. I don’t know what a BIRD and isolator relay cost, but it probably is close. That is what I plan to do if my BIRD or Trombetta goes bad. You’re right to replace them. It’s nice to be able to plug in and charge up both at the same time. Especially if you Store for any length of time.

[Mo_Mike]

Originally Posted by rvschneider

Thanks guys. Went out to the camper today and thought I had solved the mystery. One of the two red fuse holders didn't have a fuse in it. Thinking I had figured it all out, I put in a new 7.5A fuse, and...nothing. Still the same result. But I did find a part number on the BIRD, or whatever it's called. It's an Intellitec 00629-120 isolator relay. I'm wondering if the Aux Start switch is part of the problem. It is connected to the same terminal on the isolator relay as the red wire from the BIRD.

I like the idea of the BIM 160, so I may look into it as oppose to buying another one of these relays.

Just wondering where these "two red fuse holders" were? I was wanting to see if my issue was a bad fuse before I started rewiring the red wire from the BIRD...

[Oneilkeys]

Originally Posted by Mo_Mike

Just wondering where these "two red fuse holders" were? I was wanting to see if my issue was a bad fuse before I started rewiring the red wire from the BIRD...

In my configuration from the factory, I only had one fuse in the line to the orange ignition wire. I had no fuse, that I could find, in that red wire coming from the BIRD. When I cut the red wire (coach battery) I put a fuse in that line too. If your problem is the chassis battery is not charging on shore power or generator, I would check two things before I bought another BIRD.
1. Under shore power/generator, do you have power to coach battery side of the Trombetta? You should have the same voltage as at your coach batteries (13.1-14.1v or so). If you do, everything is working up to there and it isolates the problem to the BIRD/Trombetta.
2. Now you need to see if either the BIRD/Trombetta is bad or if the wiring is the problem. The easiest way to check that is to cut the red wire coming off the BIRD, plug into shore power/generator and check the voltage of that wire at the end not coming out if the BIRD. That wire should be feeding the BIRD the same voltage as at the coach battery. (Mine was hooked up incorrectly at the factory) if that voltage reads the same as at the coach battery, then the BIRD is wired correctly and your problem is probably a bad BIRD/Trombetta. If the voltage from that wire is not the same as the coach battery, put a 5 amp fuse in line with that wire and hook it up to the coach battery side of the Trombetta. Now the voltage from that wire will feed the correct voltage to the BIRD and it should work correctly. That is what I did and it has worked for two years without a problem.

[Mo_Mike]

Originally Posted by Oneilkeys

In my configuration from the factory, I only had one fuse in the line to the orange ignition wire. I had no fuse, that I could find, in that red wire coming from the BIRD. When I cut the red wire (coach battery) I put a fuse in that line too. If your problem is the chassis battery is not charging on shore power or generator, I would check two things before I bought another BIRD.
1. Under shore power/generator, do you have power to coach battery side of the Trombetta? You should have the same voltage as at your coach batteries (13.1-14.1v or so). If you do, everything is working up to there and it isolates the problem to the BIRD/Trombetta.
2. Now you need to see if either the BIRD/Trombetta is bad or if the wiring is the problem. The easiest way to check that is to cut the red wire coming off the BIRD, plug into shore power/generator and check the voltage of that wire at the end not coming out if the BIRD. That wire should be feeding the BIRD the same voltage as at the coach battery. (Mine was hooked up incorrectly at the factory) if that voltage reads the same as at the coach battery, then the BIRD is wired correctly and your problem is probably a bad BIRD/Trombetta. If the voltage from that wire is not the same as the coach battery, put a 5 amp fuse in line with that wire and hook it up to the coach battery side of the Trombetta. Now the voltage from that wire will feed the correct voltage to the BIRD and it should work correctly. That is what I did and it has worked for two years without a problem.

Thank you sir for your help! Cut the wire from the coach batteries and checked voltage to the BIRD. 0 VOLTAGE, 0 Voltage idle and 0 voltage when on SHORE POWER. No wonder nothing was happening when SHORE POWER was connected. Connected a fused lead from the ORANGE wire to the BIRD to the COACH BATTERY post of the TROMBETTA. Worked like a champ. Alternator charges COACH and CHASSIS, and SHORE charges CHASSIS and COACH. (didn't check with GENNY yet, but should work if SHORE POWER does)

Only thing is that the COACH BATTERY is connected to the IGNITION LEAD of the BIRD, while the CHASSIS BATTERY is connected to the BIRD's COACH BATTERY lead... You got to love THOR and their wiring.

I didn't correct the connections, but figure if things don't work, I will swap them...