# USA Trains GP9



## pwiegner (Mar 9, 2008)

Hello, i`m new to LSO and call for help from Germany. 
I´m going to install an ESU Loksound XL decoder in my nearly 10 years old GP9 from USA Trains.
It shall work in DCC mode.
Everything works fine besides the front and rear lighting. I think I shot some of the bulbs and LED´s 
when connecting the small boards to the decoder.
Any suggestions what can be done? 
Peter


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## Engineercub (Oct 18, 2008)

Guten Tag Peter! Ich heiße Will. 
You can call USA Trains for replacement parts. They are very friendly and will help you. The replacement parts are not usually too expensive. If calling them is a problem from Deutschland let me know and I can call them for you. Just let me know what parts you need replaced. Also, what road name is your GP9? Some are no longer available. 

Chuße! 

-Will


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## Greg Elmassian (Jan 3, 2008)

Peter, if you have the low voltage boards, the bulbs are about 5 volts. You can get the screw-in bulbs, but forget finding the 5v grain of wheat bulbs, I have ordered them 4 times, at 3.50 each and always got the 12v ones... My advice is to find those in other places... I have listed the part numbers on my site, go to the bottom of this page:

http://www.elmassian.com/trains-mainmenu-27/motive-power-mods-aamp-tips-mainmenu-35/usat-motive-power-mainmenu-36

Regards, Greg


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## Axel Tillmann (Jan 10, 2008)

Hi Peter (Guten Tag):

First of all you can give me call +1 (508)-529-9166 if oyu need more help and want to discuss this in German. But the short and the long of it. Most DCC decoders I know hacve +24 Volt as they common Plus (actually I only not ZIMO 69V and 690V have true Voltage regulation - but there may be others I don't know all types in the market). Now I blew mnore than once (being forgetful) 5V bulbs after converting to DCC. Out of the box and depending how you connected the bulbs you may have operated them with 24V for about 3 seconds







and then puff. While you can (I think on most DCC decoders) manipulate the average Voltage to be lower you are never acutalually getting 5V to the Bulb you are just getting short impuleses of 24 V. Longterm your 5V bulbs will not live as long







. So it would be better to replace the bulbs with 24V bulbs and don't regulate common DCC+ down. On my Zimo conversion of the GP9 I ripped all the USATrains guts out and connected everthing directly. I used a terminal block and connected the ribbon cable to it and then the individual llamps, smoke etc. to the terminal block and the speaker (it was a TrueSound DCC conversion) to the other side of the board.

Good luck.


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## Greg Elmassian (Jan 3, 2008)

Many USAT trains have 2 electrical versions... early versions typically used 5 volt power to the boards at each end of the loco... later ones use track voltage... I burned mine out too on my GP7.... 

Axel, the GP7 is not so simple, the boards have the headlights, number board lights and bicolor leds for classification lights. 

If you are doing a DCC conversion and want the lights to work like they did on DC, it's simpler to wire them all separately. 

Regards, Greg


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## Michael Glavin (Jan 2, 2009)

I recently did some light board hacking on several USAT GP's, biggest problem as I recall was decoders use positive and or + wire for a common and switch the negative - wire on-off for each function, whereas the USAT and others are wired with negative - commons. This holds true for LED and incandescent lights. 

I replaced my number board light bulbs with the same size/type screw in midget E5 or T1 bulbs with 12V units # 272-1143, for the cab lighting I used a grain of wheat 12V bulb # 272-1141 and drive both with 5V for more prototypical lighting power (the stock bulbs give my Engineers a sun tan and over power the number boards too). I replaced the wimpy headlights with 5mm high intensity Led’s with the appropriate resistor all was found at my local Radio Shack 

I also found a replacement bulb for the stock number boards at my local Radio Shack stores, albeit there 6V which is NO problem # 272-1142.

The bi-directional marker/classifaction LED’s are a problem too. If you feel the need you have to replace these with a common anode LED’s verses the atypical common cathode LED’s their equipped with from USAT. I looked high and low for replacement common anode bi-color LED’s these are hard to find, I found a source in Germany! Thing is after all this I found the directional markers or classification lights are typically not used on diesels, go figure.

I also now have a selection of lighting products on hand from Minatronics, they are a specialty hobby supplier for lighting, switches, and various electronic boards that drive or simulate flashing beacons, Mars lights and more. 

http://www.miniatronics.com/Merchant2/merchant.mvc

As Greg alluded to, it’s best to wire all the lights individually IMO or at least in like groups to take full advantage of the DCC lighting features of most decoders. 

Regards,
Michael


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## pwiegner (Mar 9, 2008)

Thanks to all contributors (up to now). I guess I got enough useful hints to carry on. When I get stuck I´ll call again. 
A special notice to Will: the loco is in UP livery, engine No. 720. 

Regards 
Peter


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## Engineercub (Oct 18, 2008)

No problem Peter. I believe USA Trains still carries the UP GP9 and parts should be easy to get if you need them. 

-Will


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## Greg Elmassian (Jan 3, 2008)

They have parts, but they do not have the 5v headlamp bulbs as I mentioned before... and since I ordered them 3 times, and was promised each time I would get the 5v ones (newer units are 12v boards) I have a handful of 12v GOW headlight bulbs at $3.50 EACH... so spare yourself the trouble and do not order those. As I said, the screw in number board bulbs are available in 5v from USAT. 

I'm just trying to save Peter the frustration. Mike in parts is the guy you want to talk to, and you can ask him about the great effort we tried to get the right headlight bulbs, he definitely remembers this and my name... we finally gave up... 

Regards, Greg


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## aceinspp (Jan 2, 2008)

Yep they got lots of parts except for the proper bulbs. When the time comes I'll have to go to Gregs parts depot for the bulbs







Later RJD


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## Greg Elmassian (Jan 3, 2008)

I got 100 6v bulbs from HK for $13 so I will send you some in your next "care package" RJ.... 

Regards, Greg


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## George Schreyer (Jan 16, 2009)

schematics of an early GP9 can be found at 

http://www.girr.org/girr/tips/tips5/gp9_tips.html


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## pwiegner (Mar 9, 2008)

Thank you George, very helpful.
Peter


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## George Schreyer (Jan 16, 2009)

This GP9 is the ONLY one that I have seen the insides of and its and old one. It appears that USAT has made some changes so my schematics are a bit dated. Newer units use either 5 or 12 volt internal lighting, mine is all track voltage. 

Newer locos may also have 5 switches on the bottom, mine has 4. 

you'll need to compare what you see inside to the photos on my page to determine if my diagrams apply to your loco.


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