Author Topic: Athearn Yellow Box DCC Ready GP35 issue  (Read 12444 times)

CPRail

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Athearn Yellow Box DCC Ready GP35 issue
« on: August 23, 2016, 08:48:15 PM »
Hi Group,

I just finished installing a LM-2S and an iPhone speaker into an Athearn Yellow Box DCC Ready GP35. When I put it on the track, it barely runs and I get the motor overload error. This engine previously ran great on good ole DC, so I'm miffed as to what's wrong.

LM-2S is plugged into the 9 pin plug and is laying upside down on the Athearn board towards the cab. 2 brown wires to the iPhone speaker with it laying on top of the 8 pin plug on the Athearn board towards the rear, with the speaker opening in the Dynamic Brake area.

The only tweak I did was to install a longer wire for the rear truck connection as the factory one broke - soldered to the clip on the truck, and attached to the board using the square black clips.

Any thoughts as to what I did wrong?

Ian Lisakowski
The Great White North
Ian Lisakowski
Modelling CP Rail & VIA in the early 80's

KPack

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Re: Athearn Yellow Box DCC Ready GP35 issue
« Reply #1 on: August 23, 2016, 09:49:10 PM »
The Athearn DCC-ready locomotives are hit-or-miss honestly.  The motor is usually high-draw and the drivetrain is questionable.  I have an old blue-box Athearn that runs with a LM-1 drawing 700mAh at full load motor current.  But I spent some time tuning the motor and the drivetrain to get it to run well....otherwise it would've probably been over the limit. 

I have another Athearn DCC-ready locomotive that I placed several different Athearn motors into it in an attempt to get it to run better.  In the end I finally trashed the Athearn motors and placed a Kato motor in there.  Now it is one of my smoothest runners.

Here's what I would do on yours....First, put it on stands and run it for a long time in both directions on DC.  That will help break in the gears.  Better yet, take the trucks apart and fine-tune the gears with a small file.  Get rid of any burs and rough edges.  Then put some pumice or toothpaste in the gear tower and run it for a bit to smooth everything up.  Clean it all out and put some quality lube in there.   You can try messing with the motor, but honestly it's probably best to just swap it out with a Kato or similar.  The older Athearn motor will never be as smooth or low-draw as the higher end motors and takes up way more space. 

For the record, I have done the above with all my Athearn blue box and "DCC-ready" locos.  They have all had the gears reworked and tuned, and all (save the one) have had the motors replaced with Kato.  As such they are some of the nicest running locomotives I have now.  Better than Genesis, and pretty much on par with Atlas. 

-Kevin

PS - one last thing.....check for anything binding on the drivetrain.  The module may be pushing some wires down on the driveshaft which is causing it to bind.

emd_16645

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Re: Athearn Yellow Box DCC Ready GP35 issue
« Reply #2 on: August 24, 2016, 09:53:59 AM »
I have an Athearn RTR GP35 (my only one) that has major motor problems.  Haven't tried putting Railpro in it, but it didn't play nice with the DCC chip I put in it (loud buzzing from motor, little/no movement).  Ended up stripping the decoder and shelving the unit.  Maybe someday I will get back to it....
Chris Bellows
Somerset Junction, 1980
somersetjunction.blogspot.com

KPack

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Re: Athearn Yellow Box DCC Ready GP35 issue
« Reply #3 on: August 24, 2016, 11:59:42 AM »
I forgot to mention....the locomotive I talked about above that went through several motors before replacing with a Kato, was also an Athearn RTR GP-35.  Back when I used DCC it fried a Tsunami because it ran so bad.

Moral of the story: Athearn RTR GP35's are bad.  Replace the motor with Kato and be happy.

-Kevin

CPRail

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Re: Athearn Yellow Box DCC Ready GP35 issue
« Reply #4 on: August 24, 2016, 01:48:46 PM »
I'll have to take a further look at the wee beastie.

As I mentioned, it ran perfectly fine on DC for that past couple of years. I only chose it for a RailPro install as it had the 9 pin plug and I'm trying to ease myself into installs, thus starting with the supposedly easy stuff first. Other than having issues with a speaker location, my two Athearn RTR SD40/SD40-2s went surprisingly easy.

I'm confident the GP35 has been all broken in, as I wasn't experiencing any issues other than it being a slower starter than the Atlas GP38 that was it's running mate.

Stay Tuned!

Ian Lisakowski


Ian Lisakowski
Modelling CP Rail & VIA in the early 80's

CPRail

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Re: Athearn Yellow Box DCC Ready GP35 issue
« Reply #5 on: August 25, 2016, 09:13:59 AM »
UPDATE - apparently the unit just needed a good cleaning. Wheels and commutator were both quite dirty. Cleaned them all up and unit did the Load Test at about 510 mA. Not perfect, but workable.

Ian Lisakowski
Ian Lisakowski
Modelling CP Rail & VIA in the early 80's