# Airwire install troubleshooting in new Bachmann Climax



## dmcchaser (Dec 31, 2015)

Hello all,

I hope this is the right place for this question.

I just installed an Airwire Convrtr 25 in my Bachmann Climax. The Convrtr appears to be connected to the T5000 transmitter, but I am getting no response or life at all from the locomotive.
I have been Googling to the best of my ability, but I have not found any good troubleshooting information yet.

Before hooking it up I did verify battery lead polarity. I have a bright green LED on the Convrtr with power switched on. I have a bright red LED on the Convrtr with the T5000 transmitter powered on.
I have approximately 14.8 volts at the battery connection on the Convrtr, however I only have approximately 1.4 volts on the wires from the Convrtr to the decoder in the locomotive.

I have the wires from the Convrtr hooked to the "18v" screw terminals on the main board of the locomotive. The switched on the back behind the sand bins are set to MOTOR-ON, PICK UP-BATTERY, LIGHTS-DCC, POLARITY-LARGESCALE. The switch behind the smokebox door (I assume for the smoke unit) is set to off. 

I have gone over the wiring diagrams in the Convrtr manual several times, and it looks like I have everything wired up correctly, but I still feel like I am missing a crucial piece of the puzzle here.

Any help would be greatly appreciated.
This is also my first foray into DCC, so please bear with me - I'm climbing the learning curve as quickly as I can.


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## Dan Pierce (Jan 2, 2008)

When using DCC the track power (read converter goes to the digital decoder track input). The decoder creates the V+ voltage but takes the digital signal separately from V+ and sends it to the electronics in the decoder. If you feed a digital signal to the V+, you will not get the digital signal to the electronics.


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## Jim Agnew (Jan 2, 2008)

Set the smoke switch to “DCC” . All switches must be on DCC setting.


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## Paul Burch (Jan 2, 2008)

What decoder address are you using? Both the convrtr and decoder set to the same address.? Default would be 3 for both.


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## dmcchaser (Dec 31, 2015)

Dan Pierce said:


> When using DCC the track power (read converter goes to the digital decoder track input). The decoder creates the V+ voltage but takes the digital signal separately from V+ and sends it to the electronics in the decoder. If you feed a digital signal to the V+, you will not get the digital signal to the electronics.


Thank you for the reply Dan. I'm afraid my knowledge of how DCC works isn't enough to understand how to apply it to my situation. I'm not certain what questions to ask for clarification either. 
I do appreciate the response, and will keep this for reference.


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## dmcchaser (Dec 31, 2015)

Jim Agnew said:


> Set the smoke switch to “DCC” . All switches must be on DCC setting.


Thank you Jim.

I tried setting the smoke switch to DCC this morning. There was no change in operation. I think I have another issue as well.
Just for my own knowledge, what does that switch in the smokebox do? I assumed it just hooked the smoke unit to track power on "track" and used the DCC board to control the voltage on "DCC" when that setting is selected. Wouldn't setting the smoke unit switch to "off" just disconnect the smoke unit from operation? 
I am not questioning your advice, I'm just trying to understand how this system is supposed to operate.

Thank you again for your help.


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## dmcchaser (Dec 31, 2015)

Paul Burch said:


> What decoder address are you using? Both the convrtr and decoder set to the same address.? Default would be 3 for both.


Thank you for the reply Paul.

I believe I have both the Convertr and the decoder set to 4 now. (The locomotive cab number)
It is entirely possible that I have messed up that setting in the Convertr or the decoder when I was changing it.
I followed the instructions in the Convrtr manual for changing the cab number, but this is the first time I have ever done this.
After work today I will attempt to restore them to defaults and try again.
Alternatively, is there a way to verify that everything is set to the correct address? (I think that's the right term)


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## Jim Agnew (Jan 2, 2008)

dmcchaser said:


> Thank you Jim.
> 
> I tried setting the smoke switch to DCC this morning. There was no change in operation. I think I have another issue as well.
> Just for my own knowledge, what does that switch in the smokebox do? I assumed it just hooked the smoke unit to track power on "track" and used the DCC board to control the voltage on "DCC" when that setting is selected. Wouldn't setting the smoke unit switch to "off" just disconnect the smoke unit from operation?
> ...


Didn’t make sense to me either, but after talking to Al at AirWire, I had success with 2 installs. 
BTW, does your Climax have sound?


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## dmcchaser (Dec 31, 2015)

Jim Agnew said:


> Didn’t make sense to me either, but after talking to Al at AirWire, I had success with 2 installs.
> BTW, does your Climax have sound?


I will make sure I keep that smoke unit switch in the DCC position.
My Climax does have the factory installed DCC and sound unit in it.


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## dmcchaser (Dec 31, 2015)

Here is the update on my progress this morning.

Overall the locomotive is still unresponsive, however I am learning more about this Airwire system and I'm gathering data.
I reset the Convrtr back to factory specifications just in case I had messed up a setting in it somewhere. 
I have installed a 1ohm resistor per the instructions. 
At the wires from the Convrtr to the DCC board in the locomotive I still have only 1.4 volts. However there is a slight voltage change every time I input a command on the T5000 controller. So far I've observed a drop as low as 1.28 volts, up to a max of 1.78 volts depending on what button is pressed.
I don't have an oscilloscope at home to confirm my suspicion, but I understand this to be an effect of whatever command signal the Convrtr is sending to the DCC board.
If I am understanding correctly this means the Convrtr is receiving control inputs from the transmitter as it should be. So one part of the puzzle is in place now.

I'm not certain what my next tests should be.


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## Greg Elmassian (Jan 3, 2008)

The DCC signal is AC, square wave, but AC... be sure you are using AC range on meter.

The voltage should be way higher than 2 volts.... 



something is fundamentally wrong... disconnect the output from the convrtr and measure voltage, should be constant... and higher...


Greg


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## dmcchaser (Dec 31, 2015)

Greg Elmassian said:


> The DCC signal is AC, square wave, but AC... be sure you are using AC range on meter.
> 
> The voltage should be way higher than 2 volts....
> 
> ...


When I disconnect the output and measure voltage am I looking for volts AC or volts DC?


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## Greg Elmassian (Jan 3, 2008)

OK, I am repeating myself...



So, the convrtr outputs DCC, DCC is a square wave of constant voltage and variable frequency. A square wave is a form of AC



You cannot use a DC meter to measure DC.


Not all AC meters can measure square wave AC properly, but your voltage measurement is way off, unless you were on DC, then it is meaningless


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## dmcchaser (Dec 31, 2015)

Sorry you feel like you're repeating yourself. I just want to make sure I understand correctly before taking measurements so I don't invalidate the test results.

I'm using a Fluke 87V for testing.

Measuring the voltage from the Convrtr with the wires disconnected from the DCC board I have 15.41 volts AC. 
I also have that 15.41 volts AC at the input terminals on the DCC board once I connect the wires again.

It appears the Convrtr is doing its job and outputting voltage, it's just AC voltage instead of the DC I was expecting. 

Now I need to figure out how to get the DCC board what it needs.
My suspicion is that the DCC board is set up to have plain DC battery voltage instead of AC voltage with the DCC signal mixed in coming in on the battery connection terminals.

What is the correct way to connect the wires from a Convrtr to a factory Bachmann/Soundtraxx DCC board?


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## dmcchaser (Dec 31, 2015)

Well, I've located one of the main problems -- hopefully it's the only problem.

The PICK-UP switch on the factory Bachmann board has a cold solder joint. There is no electrical continuity between the trace on the board and the switch terminal. 

I'll solder that back up and report back with the results.


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## dmcchaser (Dec 31, 2015)

That cold solder joint was the culprit. Once that was repaired everything works as it should.

Thank you everyone who helped me figure this out.


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## Greg Elmassian (Jan 3, 2008)

The 14.41 volts you report in post #14 is much better than the 1.4 volts you report in post#1. (I gather, but you do not state you were on DC measurement)


DCC boards (decoders) NEVER reject the DCC square wave. If presented with a constant DC, they will usually operate by passing the DC through to the motor, although they can be configured to ignore DC.


When presented with PWM, which is what almost every "DC powerpack" presents, the results can be unpredictable.


Good debugging on the Bachmann wiring, poor assembly and solder joints are often the hallmark of the mainstream Chinese built products, Aristo and Bachmann are pretty famous for this, weird color codes, red wires painted black, black wires painted red.


(The factory runs out of black wire, they paint the red wire with black paint, no kidding)


Congrats on beating the system!


Greg


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## Timit1962 (Jun 11, 2020)

Hi ive just completed my first deadrail install in my Bachmann Annie ( version 6)using a Tam valley receiver and transmitter linked to my roco z21. I was really interested that you had successfully converted your climax to airwire and i was hoping to do the same with mine which is also stock dcc sound ( soundtraxx) model. My question is that can i follow the same approach and connect my powered Tam valley receiver to the 18 v terminals as you have with the airwire and using the same switch settings. Also i was intetested in where you had located the batteries to power your airwire converter. Thanks for your help. Timit.


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## dmcchaser (Dec 31, 2015)

Timit1962 said:


> Hi ive just completed my first deadrail install in my Bachmann Annie ( version 6)using a Tam valley receiver and transmitter linked to my roco z21. I was really interested that you had successfully converted your climax to airwire and i was hoping to do the same with mine which is also stock dcc sound ( soundtraxx) model. My question is that can i follow the same approach and connect my powered Tam valley receiver to the 18 v terminals as you have with the airwire and using the same switch settings. Also i was intetested in where you had located the batteries to power your airwire converter. Thanks for your help. Timit.


I took a brief look at the Tam Valley website to see how their system works, and it looks like it should connect to the locomotive the same way the Airwire receiver does.

Right now I have the battery pack setting in a gondola behind the locomotive, at least until I come up with a more permanent solution. I'm going to try to fit a custom battery into the bunker above the circuit boards, but I don't know if that'll work -- there's not a lot of room in there.


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