TMCC with Chuff Generator Only goes in reverse

If you’re tossing a breaker, you’ve got a short somewhere. Time to retrace your steps. …check your antenna connections too, be sure the handrails are not touching metal,…..this ain’t the chuff generator causing this….if this Oddesy, be sure the magnet hasn’t splintered and touching things it shouldn’t be,….

Pat

I agree with Pat but also I would pull the boiler off and run without it. Could be a wire gets jammed or rapped into the drive train in the forward direction of the spin.

I’ve taken the boiler off and ran it both directions.  In reverse it works fine. When you try to add throttle in forward everything flashes and dims and then the breaker pops.  Do you all think I have a bad FET driver?

@BeefyT posted:

I’ve taken the boiler off and ran it both directions.  In reverse it works fine. When you try to add throttle in forward everything flashes and dims and then the breaker pops.  Do you all think I have a bad FET driver?

Aim small, miss small,…..start with simple diags, then graduate to flux capacitors,…with the engine off, try rotating the flywheel by hand, observing anything binding, both forwards, & backwards, …..look for anything that possibly could have gotten onto the pins of the boards, …a stray solder blob, a screw, hunk of wire, etc,….how is it in neutral under command?….can you control functions in neutral??…whistle, bell, etc,….look at your Oddesy equipment, sensor, magnet ring, etc,…anything busted, or gangled up,…..The driver certainly could’ve taken a poop, but check simple stuff first before condemnation,….

Pat

@harmonyards posted:

Aim small, miss small,…..start with simple diags, then graduate to flux capacitors,…with the engine off, try rotating the flywheel by hand, observing anything binding, both forwards, & backwards, …..look for anything that possibly could have gotten onto the pins of the boards, …a stray solder blob, a screw, hunk of wire, etc,….how is it in neutral under command?….can you control functions in neutral??…whistle, bell, etc,….look at your Oddesy equipment, sensor, magnet ring, etc,…anything busted, or gangled up,…..The driver certainly could’ve taken a poop, but check simple stuff first before condemnation,….

Pat

Yeah, everything works like it should until I put it in forward.  Neutral, reverse, and forward have horn whistle and chuff.  When I advance the flywheel by hand it still triggers chuffs but as soon as I add throttle the lights dim and the breaker throws.  There is a melted grommet or washer on one of the FETs that’s why I asked if it might be one of those and if that might be why it can go in reverse and neutral but struggle in forward.

Sounds like you’ve got a lunched driver,….but make sure something didn’t take the driver to lunch, ……..look at all your wiring, motor leads, etc,….unfortunately with Lionel ditching TMCC parts, your repair options are limited to an ERR cruise M upgrade, …..which will be an upgrade with 100 speed steps, etc, etc,…there’s a bit more involved with this particular engine, given the IR, and some lighting functions, but there are work arounds for all of that too,….

Pat

Also a good idea to check the motor function itself just to be on the safe side, …I know you said it runs, but like I mentioned, something scorched your driver, just make sure it’s self inflicted by the driver itself, and not something else,….a simple DC source with the wiring disconnected at the motor leads can tell the story,…last thing ya wanna do is install a new driver only to find out the motor threw a left hook,..

Pat

I had a similar problem with a jlc gg1. Going in reverse was my problem. Found a pinched wire which was shorting out the fet when it was in reverse. Fixed the wire and replaced the fet in the odyssey board. You most likely have a short in the forward circuit. You may have pinched a wire when you installed the chuff generator.

I have a driver board that may work if you don’t want to go the ERR or possible repair route. You didn’t state the product number so I went with the TMCC version of the M1a. This was removed from a L2a Mohawk. The part numbers seem to match up except mine has a different sticker applied.

From Lionel.

This is out of my Mohawk. Let me know if you want to give it a try.

It is frequently possible to replace the driver FET(s) on the DCDS, don't give up on it yet.

@Dave_C posted:

I have a driver board that may work if you don’t want to go the ERR or possible repair route. You didn’t state the product number so I went with the TMCC version of the M1a. This was removed from a L2a Mohawk. The part numbers seem to match up except mine has a different sticker applied.

From Lionel.

This is out of my Mohawk. Let me know if you want to give it a try.

How much you want for it?

Cost of shipping. I sent you an e mail.