Help: TAS UCUB-AC installed in Lionel F-3 with dual pullmor motors

Well the hardware fault could be the reverse transistors/FETs or it's control circuit failed.  Otherwise are there any lockout switches for single direction?  Does this use the add on R2LC if so does it work in another engine?  G

Are you sure all the wiring is proper?

Only three wires go to the motors.

yellow to yellow (brush 1)

blue to blue (brush 2)

green to green (field)

As far as I can tell, the other field wire on the motors go to outside rail.

There two sets of jumpers on the bottom board of the UCUB. I have no idea how they should be set.

If you're running it in conventional mode for testing, note that the PGM/RUN switch in PGM will lock it in a single direction.

No conventional. TMCC only.

Using the CAB1, address engine, turn knob and engine moves forward.

Hit Dir, engine stops, turn knob and no movement.

Use the forward and reverse buttons instead of the direction button in TMCC.

Aren't those coupler buttons?

Flash, did the engine run fine before the mod?  Some times motor bearing issue, or armature plate alignment can cause a motor to run one direction and jam in the other.  You should hear it or see the motor attempt to move.

Since it runs forward your wiring is fine.  Now you need to start eliminating issues that can cause this.   G

George may be correct in his analysis, it could be one of the triacs has bit the dust.

John Does this use a plug in R2LC or is it a like the older LCRUs  I am not as familiar with UCUB.  G

Oh yeah.

I've never used TMCC.  Is there a stall setting that has to be reset?

Switch the motor brush leads at both motor, if it goes backwards OK, this is probably it.

I just looked this up for clearing the stall setting:

Clear stall setting (Engine or Train):

- Address Engine or Train

- Press SET twice, one second each time.

I don't think this is it, though, the direction button should reverse the train at the stall setting.

I have never used it, but the manual doesn't mention the R2LC, and none of the configuration instructions suggest one is used.

This was designed to use all sorts of sound boards, a jack of all trades.

You can check them with a meter.

Check Triac with MultiMeter

Yes, it has a plug in R2LC that goes into the bottom board.

The top board accept the RS4 and amp boards.

Surprising the manual doesn't say anything about the R2LC!  I'd try a new R2LC first, as the forward and reverse motion commands come from the R2LC as PWM signals.  If it's not the R2LC, another common failure is the opto-coupler that feeds the triacs, I've replaced a number of those on DCDR modules.  Unless the triacs were shorted, they're less likely to be bad, but anything's possible.