Proto 2000 GP9 running issues.


chessie_system3

Well-Known Member
I posted earlier today about the issues with my GP9. Now I run just standard DC on my layout. It was running fine then just lost all power and went into a limp mode. At half throttle my locomotive just shudders in both directions. I know it's not a track issue as my other locomotives run fine. I did clean the wheels as a precaution or rather in hopes it would return to it's old self again. No luck on it. I have already replaced the axle gears as well. I also noticed that the light on my throttle flickers when I'm running the GP9. It's a constant light with the others with no flickers. Any ideas on what's going on with it?
 
What does the light on your throttle tell you? Other possibilities, the peanut butter P2K used for grease needs to be cleaned out of the trucks and replaced with grease/light oil, or if it is found to be the motor, one of the armature winding wires might have broken. Just to rule it out, I would also check the axle gears.
 
The light flicker on my throttle let's me know something is off voltage wise. It shouldn't need a lube job as I havent had it that long. It was lubricated when I installed new axle gears to replace the cracked ones it came with. However anything is worth a look. If I get time tonight I'll take the shell off and have a look see at it.
 
I remember those engines had a weird circuit board that lowered top speed of the motor, and reduced voltage to the light bulbs. It’s possible one of the componenets of that board has failed.
 
So brought the GP9 up last night and had a look see. Found nothing out of the ordinary. I removed the 8 pin board and the actual circuit board itself. I didnt see anything. Inspected the can motor. I didnt see anything there. Same with the wires. So feeling defeated I started putting the shell on. Then I noticed it. My shell was hitting and pulling one of the ground wires to the board. Took the shell off. Rechecked the ground. Made sure the cap was in place. Installed the shell and put it on the layout. It ran without any issues. Back to it's normal self again. So best guess is the pulling of the ground wire was causing my issues. However I'm going to monitor it to see if anything else happens to go wrong with it.
 
Is this one of the older (LifeLike era) Proto2000 GP9's?

If so, could it be the axle gears?
This was a VERY common problem on those engines. Could results in a lot of "clicking and jumping" of the loco, or if they're all badly cracked, it might hardly move at all.

It's also very easily fixed.
Athearn part number 40028 40" wheel assemblies will drop right in.
Walthers also sells replacement wheelsets.
Or, you can buy just the gears themselves.
Numerous youtube videos on this problem. Check them out.
 
Is this one of the older (LifeLike era) Proto2000 GP9's?

If so, could it be the axle gears?
This was a VERY common problem on those engines. Could results in a lot of "clicking and jumping" of the loco, or if they're all badly cracked, it might hardly move at all.

It's also very easily fixed.
Athearn part number 40028 40" wheel assemblies will drop right in.
Walthers also sells replacement wheelsets.
Or, you can buy just the gears themselves.
Numerous youtube videos on this problem. Check them out.
Thank you for your response. This is an older one. Going off of the data board this one is a 99 one. As for the gears I bought it with cracked gears. Ofcourse seller didnt say anything about that. However I replaced the gears with athearn gears when I got it and found out they were cracked. Wheels were gauged with an nmra gauge so that's good there. Now I can say from what I found and how it acts currently there is still something wrong with it. It's never been completly right to begin with. However it is back to where it was at before I had any real issues. It takes a good deal of throttle to get it going. It takes about 55% throttle to get it to road speed when mu other locomotives take about 30-45% throttle. Perhaps you are on to something with the gears. Worse case scenario I'll have to replace a motor in it.
 
Thank you for your response. This is an older one. Going off of the data board this one is a 99 one. As for the gears I bought it with cracked gears. Ofcourse seller didnt say anything about that. However I replaced the gears with athearn gears when I got it and found out they were cracked. Wheels were gauged with an nmra gauge so that's good there. Now I can say from what I found and how it acts currently there is still something wrong with it. It's never been completly right to begin with. However it is back to where it was at before I had any real issues. It takes a good deal of throttle to get it going. It takes about 55% throttle to get it to road speed when mu other locomotives take about 30-45% throttle. Perhaps you are on to something with the gears. Worse case scenario I'll have to replace a motor in it.
Justin, the problem is that weird circuit board I referred to earlier. If you look closely at it, there are several resistors on it to reduce the voltage going to the motor, as well as the light bulbs. If I didn't know it would blow the light bulbs in less than a half a second, I'd suggest removing it completely and wiring the motor straight. You can still do that, but you'd need to put resistors in line with the bulbs, or leave them disconnected.
 
Justin, the problem is that weird circuit board I referred to earlier. If you look closely at it, there are several resistors on it to reduce the voltage going to the motor, as well as the light bulbs. If I didn't know it would blow the light bulbs in less than a half a second, I'd suggest removing it completely and wiring the motor straight. You can still do that, but you'd need to put resistors in line with the bulbs, or leave them disconnected.
I meant to respond earlier to you and completely forgot. I inspected the board. I even compared it to my GP7. I even went further than that and switched the boards around. So with that being said. The GP9 has the GP7 board in it and the GP7 has the GP9. Both seem to run fine. As I did take the board issue into account that you mentioned. Atleast look at the resistors on it. Could the board look good and be bad? Why only the GP9? My guess is going to be either the motor or gears that are the issue with it. All things told it does still run just takes a decent amount of throttle to get it going.
 
Justin: How many hours of operation does the locomotive have recorded? It just may need some additional run time to break-in all te moving parts. I have locomotives that showed the same slow starts as yours and with time the locomotives movements smoothed out. I have several of Proto GP 7 and GP 9 locomotives and each runs slightly different.

Greg
 
Since this is probably an older Proto GP9, have you COMPLETELY disassembled the trucks, and cleaned out all the peanut-butter like "lube" that was originally installed into them...?
 



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