KLine GG1 TMCC Response Problem

I would check the TMCC antenna (inside the shell of the engine ) first before jumping straight to the suspecting the boards.

Good idea.  But, I'm not sure exactly what to look for there.  There is a yellow wire running from one catenary base inside the shell to the other and then to the boards.  Is this the TMCC antenna?  What do I look for?  I guess I could change the top from the good one to the other one.  The wires from the inside of the roof  (3 of them) clip to wires from the module.  Two are for lights.  The other goes to one of the catenary bases.  If its the antenna, the other base should correct the problem, correct?

Yes that is the antenna wire, AND NO part of it nor of the pantographs should be in contact with the body, frame, or any other grounded part of the locomotive. A simple continuity test with a volt/ohm meter will eliminate (or confirm) that as a problem.

IF it's not the antenna, it's likely the R2LC board, that's really the two parts that deal with the TMCC signal.

OK I have new information.  I checked the continuity with my multimeter and at first there did not seem to be any continuity (no beep from the multimeter).  The yellow wire was hot glued from the factory to the frame.  I did, however, slightly turn the wire connectors to the pins under the catenary.  I rechecked for continuity and the multimeter indicated there is continuity (it beeped).  I put the shell back on, powered the track and only the forward light came on (no sound, no run away).  I addressed the engine and blew the horn.  So far so good.  I reversed direction and the light reversed.  However, when I turned the throttle it moved about a foot and stopped.  Then it would not respond to any command.  I tried the reset process and nothing changed.

One other thing.  Three days ago when my son-in-law and I were working with it we noticed the black lead to the program switch had come off.  He soldered it back on (to the middle pin).  Could we have connected it to the wrong pin?  From right to left (looking toward the front of the engine), we were certain the black wire had come off of the center pin as there was residual solder on it.  The purple pin is to its right and the left hand pin is unwired.  There is continuity between the center pin (black wire) and right hand pin (purple wire).

It leads me to believe that the R2LC Board is defective.  It seems as if only R4LC Boards are available for purchase but the literature indicates they are backward compatible.  How hard it it to change out the board?  And, how could I check the present board to see if it it seated correctly?  Finally, where could I buy the R4LC?  Thanks for all of your help.

Program switch has a wire in the center contact and one of the end contacts. The switch is closed in program mode and open in run mode.

As long as the antenna is not shorted to shell, only the pantograph contact, it should be receiving signal. Better if you connect both pantograph contacts together.

Verify that, then try reprogramming your engine.

Pete

OK, this is really weird.  I looked under the shell to see how I might connect both pantograph contacts together as Norton suggested.  The yellow wire is connected from the tip of one pantograph to the other one so they seem to be already connected.  The wire is hot glued all along one side of the engine to the other, so I could not see how I could connect the ends; but I'm not sure what you meant Norton.  Nonetheless, on a whim I popped in the external pantographs themselves.  Everything works now!!  I haven't reprogrammed the engine yet as I didn't want to mess with success yet.  Why would placing the pantographs on the roof suddenly make any difference?

On a side note, what batteries are best for the Cab1, both in strength and/or longetivity?

I don’t have a K-Line GG1 but do have Lionel and Williams versions. I assume yours has a metal tube in an insulating washer in the roof at the center of each pantograph.

With an ohmmeter, verify with the pantographs removed you measure infinity or very high resistance between the metal center tubes and the shell. Then make the same measurement with the pantographs installed. It sounds like one or both of thr pantographs is making contact with the shell.

Pete

OK, with the pantographs removed, I measure very high resistance between the metal center tubes and shell as I should.  With the pantographs installed I get the same result.  The continuity measurement between the two pantographs is excellent.  Apparently the pantographs extend the ability to pick up the radio signal.  I was able to reprogram the engine and everything is working well.  One issue remains.  When it runs over a fastrack switch at a slow speed the sound will cut out and the light flickers. After it passes the switch the sound resumes again.  At higher speeds, this does not occur.

There should be a connector for a 9v battery in the engine. The battery should maintain sounds when power is interupted momentarily.

Pete

Thank you Pete.  I thought it was only for shutdown sounds.  I'm slowly learning.  Thank you everybody for the help.

You might want to consider the YLB - RailSounds Battery Replacement, it's a once and done battery replacement and it'll never leak.  Connect one wire to track power, plug the battery clip in, and you're done.

Thanks John.  I'll be buying those.