No forward or reverse

I opened up the engine and it had a unattached blue wire.  What does that connect to?

would help tremendously if you could give the engine item number! then someone can help you!

Alan

P.S open up the tender a take a picture would help identify your board ps2 5 or 3 volt?

The engine had a mux board, that solders to the negative lead of the capacitor, under the board. Should see solder blob.  Make sure 5 pin connector in tender connect to board. Try a reset.  After that check solder joints on engine pcb where tether plugs in for cracked solder joints at pins. Especially white and yellow motor leads. G

The item no is 30-1550-1E.  Pacific K4.

The lone blue wire comes from under a plate in front of the engine. The wire has a small solder blob on it . It is not part of any wire bundle but a separate wire. I’ll take a picture of the inside of the tender tonight.

The Mux board is the board in the shell.  That wires solders underneath it on the DC negative trace of that board, an where the capacitor is.  G

I assume this is the MUX board. I am not sure where to solder the blue wire to.

Did you try the factory reset as G suggested?

Is this conventional mode (not DCS-command) control?  What is your transformer?  Is it only the fwd/rev motion that doesn't work (what about sound, lights, smoke)?  When you initially apply power do you hear the faint relay click from within the tender?    When you change direction can you hear the relay click?

Is this something you just purchased on eBay or whatever...or did it just start doing this one fine day?

The Blue Capacitor has a white strip, that is DC negative.  On your first Mux picture on the bottom of the board is a solder joint under the capacitor with a circle and 4 dash to the capacitor lead.  Looks like a target.  It correlates to the lead on the white stripe side of the capacitor.  Solder it to that point.

Back on the tender, where the yellow and white wire go into a 5 pin connector on the back of the PS-2 board under the aluminum heat sink, make sure that is fully pressed in.

For conventional operation battery must be fully charged to come out of neutral, but DCS battery should not matter.  So the feature rest or factory reset may fix this.

If not, go to back of engine where tether plugs in and snap a picture.  Those are the pins that can crack and need to be resoldered.  Also check that motor leads attached to motor. 

Lastly picture of motor windings.  Motor can go bad.

Also check continuity of tether.  If it has a broken motor lead no movement.  But you would also lose lights in one direction or the other, depending on which wire is broken. 

When you go to reverse do you hear relay click, does reverse light on tender come on?  If so, it is not a locked in neutral issue, but rather a wiring, motor, or board problem.  G

Is this where I solder the blue wire ?

This is located directly under the capacitor. Circle with an X through it.  This is the spot you are referring to. Thank you

Yes to second picture near sticker.  May have to add solder to the joint first, then extra on wire, then solder. G

Hi G,   I soldered the blue wire to the mux board but I still have the same issue with no forward or reverse therefore I am working on your Ck list.

i did a feature and factory reset. Didn’ t resolve the issue.  I do have bell whistle and engine sounds.  Smoke unit works.  I can hear the relay pull in when I switch back from forward and reverse.

I checked the yellow and white wires under the heat sink and they appear to be fully pressed.  I pushed down with a flat head screw diver , no movement. Note attachment. Moving on to the engine wiring.

Hi G,  this is a picture of the back of the engine where the wire leads are soldered.

They appear to be intact.  I also checked the motor leads , they also seem to be ok 

This tender does not have a back up light however I can hear the relay pull in therefore  based on your previous post I assume it is not locked in neutral.

i will try to ck continuity on the tether next.

How do I take a picture of the motor windings as per your post?  Will the motor pull out from inside of the metal housing? I assume you push in on the black tabs and pull the motor out in the direction of the mph tape/disk.

Hi G, I Ckd the continuity of the teather with a multimeter and it is ok.

If you have a multimeter, measure DC voltage at the 2 motor terminals in the engine.  When in neutral the voltage should be 0, when in fwd and commanded to any non-zero speed it will be a large DC voltage of one polarity, when in rev it will be the same large DC voltage but of the other polarity.  This assumes the motor voltage is making it from the tender thru all the wiring/connectors.  The idea being if voltage is making it to the motor itself but the motor is not budging in either direction, then the motor becomes suspect.

If you do get motor voltage, you can attempt to trace back the motor voltage to the motor connector (ylw and wht wires) on the PS2 board in the tender.  It's tight quarters as your photo shows, so it may be impractical to make this measurement.

There are a couple measurements you can make on the motor itself without dis-assembly.  Disconnect the engine from tender.  Measure the resistance of the motor winding at the motor terminals.  It should be in the few Ohms range.  Rotate the flywheel to a half dozen positions of a revolution and repeat measurement. 

Then, switch to measure DC voltage at the motor terminals.  Flick the flywheel in one direction; the DC voltage should jump up to a few volts and then settle back to 0.  Note the sign (+ or -) of the momentary DC voltage.  Then flick the flywheel in the other direction.  The DC voltage should jump in the same manner but with the opposite sign.  If the motor is behaving as a DC generator, then it should at least budge, jerk, or come alive in some fashion when in fwd or rev.

Go back to the PCB at rear of engine.  It is not the pads the wires are attached too, but rather the pins in the trace under the wire.  If the solder joint cracks on the yellow or white wire pin, you will not have motion.  You might have to lift the wire up to inspect.

Having said that do the engine lights come on and stay on in when you move between forward and reverse?  If not, your not getting motor power through to the engine.

Way I check this when nothing is obvious is take both shells off, plug tether in.  Test continuity from wires at the connectors on the board in tender, to a point of the wire at the source you do not have.  In this case white and yellow wires at the motor terminal.  If no good, move towards board until you get continuity.

If that is all good you might have a bad board that needs to be bench tested and repaired if possible.  If a FET it can be.  G

G, I checked continuity from the connector in the tender to the motor terminals and the continuity for both yellow and white wires was good 

Hi Stan,  I am a novice at this and the first time I used a multimeter was to Ck the continuity from the motor leads to the teather connection on this tender.

please talk me through this. To measure DC voltage place engine and tender on track without shells. Set track power to 18 volts. Start up engine and leave it in . neutral. Turn voltage meter to DC voltage.  What number setting should I use?

touch yellow and white motor posts. Multimeter should read 0.

when I place the engine in forward or reverse at 0 mph what multimeter setting should I use?

A typical meter will have DC Voltage settings or ranges of 2, 20, 200, etc.  The setting should be higher than the expected measured voltage.

If putting 18V AC on the track, the level of DC voltage you'll see at the motor will be between 0 and ~25V.  So for this application, set it to 200V.   Remember - this is a DC Voltage setting sometimes labeled DCV on the meter; do NOT use the AC Voltage setting (sometimes labeled ACV).  

If this is your first time using a DC voltmeter, try measuring a 9V battery on the 200V DC setting.  Obviously it should read 9V DC...or maybe 8 or 7 if used.  Then reverse the red and black meter leads on the battery and note how the sign (+ or -) changes.

When you put the engine in fwd or rev at 0 sMPH, the voltage should read 0 just like neutral.  As soon as you click to 1 sMPH or higher, the DC voltage should jump up.  Go to neutral and the voltage to go to 0.  Change direction and click to 1 sMPH or higher and the DC voltage should jump up (but the sign + or -) should be opposite.  Lather, rinse, repeat!

Thanks Stan , this was a $300 eBay engine.

Hasn’t run from day one but I’ve learned a lot.

Hi Stan, I put the meter on it and it read approx -8 in one direction and a plus 8 in the other direction.  I toggled it back and for multiple times without the wheels running and suddenly they unlocked and started running???

i guess At this point I’ll put everything back together and try running it.

Do you have Any ideas why it suddenly unlocked from neutral and started working?

Since you measured + and - DC voltages right at the motor terminals...and yet the motor was not budging...I think there's a connection issue within the motor.  For example, a motor can develop a dead-spot from brush-commutator wear and tear where the applied voltage does not reach the windings.  Jog the shaft a bit and off it goes.  As long as the motor does come to rest at that dead-spot angle, you can have hours of operating enjoyment.

If you encounter the problem again, I'd run the engine with the hood off.  This may mean operating without lights depending on the engine type.  Then, if the engine won't start, mark the flywheel angle.  Manually turn the flywheel a bit and hopefully the engine will take off.  It may take dozens of run-stop cycles but let's say you again find the motor won't start.  If flywheel mark is at the same angle, then guilt can be assigned.

Perhaps getting ahead of myself, but the good news is even if the motor needs to be refurbished or replaced, this is something I'd say the average guy can do.  OTOH, if the tender circuit board was not putting out motor voltage, that typically requires replacement of tiny transistors best done by a service tech.

It was not locked in neutral since you read a voltage.  Rather it was binding, or as Stan said, possible commutator corrosion at brush interface.  Did you try manually turning flywheel to engine no binding.  On steam, you can have linkage out of place, brake detail tight against driver wheels, or some other issue in drive gears.   G 

Thanks guys, since it started running I put the shells back on and haven’t taken it apart.  One thing I noticed is that the white disk on top of the motor where the black and white striped tape is for the mph reading. That disk seemed frozen and was hard to rotate. Should that have turned freely?   This was a cheap eBay purchase  and may have set for a long period of time.

Yes,  So you had binding of the motor.  Either what I said above, maybe some debris in the gear box binding gears.  G