Need tether wiring diagram for K-line TMCC F3 6-motor ABA set K-25301

Bob,

If you cannot find a new one I think I have a couple good used ones.

Scott

Thanks Scott

If I can't find new ones, I'll get back to you. 

Bob

Does your engine run?

Marty

Lead unit runs normally.  I'm pretty sure that all 3 units run forward (I don't think the lead A is dragging the other 2).   Under TMCC, I reverse the units and I get no lights in the trailing A.  The lead A's wheels slip and train does not move.

The current tether is homemade, so I need to verify the wiring and/or get a replacement.  The prior owner says it was running normally, but it did arrive with 2 bad connections to one tether plug that I repaired.

Bob

I've never found a wiring diagram for these, you may simply have to trace out the wires and figure it out.  I thought these had 6 or 8 wires and not four.

This set has 4 wires.  I have a K-Line PRR ABA PA-1/PB-1 set that has 8 wire tethers.

I've taken 2 of the units apart so far.  There is a 4 wire plug inside the lead A, and a 2 wire plug inside the B unit. The B only needs motor power, the trailing A needs motor and lights.  I need to pull apart the last unit.

The internal plugs are intact, so I may just get replacement tethers and be done with it.  

Bob

What is in the other units?  I Upgrade an ABA set and K-Line slave the Trail Cruise board to the Lead unit.  Interesting how things where soldered on the slave boards.  As John said no diagram, so reverse engineering.  If no slave board the wiring should be straight forward as far as leads to get the Trail A motor, coupler and lights to work, but I would have thought more leads needed too?  2 for AC, 2 for Motor and 1 each for light and coupler using chassis ground as return.  G

I'm surprised they get all that done with four wires if there's no logic.  You need to isolated wires for the motors, that leaves only two for the lights and couplers.  I suppose they could return them to track common...

RRDOC posted:

This set has 4 wires.  I have a K-Line PRR ABA PA-1/PB-1 set that has 8 wire tethers.

I've taken 2 of the units apart so far.  There is a 4 wire plug inside the lead A, and a 2 wire plug inside the B unit. The B only needs motor power, the trailing A needs motor and lights.  I need to pull apart the last unit.

The internal plugs are intact, so I may just get replacement tethers and be done with it.  

Bob

If you can get the original tethers, restore it to original. It looks to be a really nice set.

gunrunnerjohn posted:

I'm surprised they get all that done with four wires if there's no logic.  You need to isolated wires for the motors, that leaves only two for the lights and couplers.  I suppose they could return them to track common...

That is how early TMCC with LCRU was done, and even Steam Modular to save harness wire.  G

Yep, and I thought it was low class back then too.   You're just asking for trouble taking your common through wheels, the track, and more wheels.

Really?  Same place the board get power in the first place.  Never had a misfire with TMCC using that method, nor PS-1 which does the same thing.  We are not flying these:-)   But run those extra wires, just don't pinch one!  G

Thanks guys

I'll let you know what I find when I open up the last unit and trace the wires.  Our modular group is displaying at the RR museum of Pennsylvania in Strasbug this weekend, so I have not had time to look at them. 

The units are from 2004.  K-25301.  The Legacy K-line site lists them as 4 motor units, but they are 6 motor. 

Bob

Take pictures.  I looked at my notes on the ABA I did.  I do believe only 4 motors.  Had K-Line Cruise 4.0 in the Lead and used a K-Line Cruise 1.0 Motor Driver in the trail unit.  G

Apparently K-Line did a number of variations with these ABA units.  I had one with six motors and they were all driven from a single stock Lionel DCDR.  Needless to say, it was working pretty hard.

I'll take all 3 units apart next week and take pictures. 

Thanks

Bob

I traced the tethers.  2 leads (black and red) power all 6 motors in the 3 units.  2 leads supply the headlight and the number board lights in the trailing A.  They are the purple wires that come off the board just below the orange disc capacitor in the picture below (they are inline with the red/black 9V battery connector wires).

The trailing unit is below.  The motor feed from the tether connects to the 2 black wires at the bottom.  They go to the small circuit board to the left which has the 2 large capacitors across the blue and brown motor feeds.  Motor power also supplies the MARS circuit board on the right.   The MARS light is only on when the motors are running and intensity varies with speed.  The other 2 leads in the tether feed the lights to the number boards and headlight.

The B unit (not shown) has the  2 motor wires tapped off the pass-through tether, and the little circuit board with the capacitors distributing power to the 2 motors like in the trailing A.

I got all 3 units working.  Besides the broken tether, the motor mount screws in the lead A were loose and the gears were slipping in reverse.

The headlight and number lights in the trailing A are still not working.  I tested the rear headlight output (purple wires) on the lead A and there is no voltage.  I wonder if the circuit was shorted when the tether wires came loose.  Is this possibly a component level repair, or does the entire board need to be replaced?

By the way, despite having rollers on all 3 units, the power pickup is in the lead A only.  There are no wires connected to the rollers in the B and trailing A.

Bob

K-Line did some interesting stuff.  G

So does Lionel and MTH.

I just got a RailKing subway set in for repair, a lot of the green marker lights didn't work for some reason.  Of the four cars, one worked perfectly, the other three all had issues.  When I opened them up, I found that MTH, for reasons I can only imagine, wired the green and red front/rear markers in parallel!  OOPS!  The green LED's run at a higher voltage than the red ones, so unless you got really lucky with the variances in the specifications, you didn't get green markers!  The difference isn't much, just .2 volts, just enough to screw things up. 

"By the way, despite having rollers on all 3 units, the power pickup is in the lead A only.  There are no wires connected to the rollers in the B and trailing A."

That doesn't make sense, what are they there for? Could there be wires missing? Is there any evidence of them having been soldered/connected to something before? Or did K-Line make all the chassis the same regardless of final usage?

Dave

DC power to the motors and lights is from the lead unit thru the tether.   They would have to add additional tether wires to tie together each units pickups for the center and outside rails.  These would carry AC of course.

The 2 pickups on the lead A unit are working fine even through some old gargraves turnouts.  

I may use the pickups to add additional lighting or other features.  Otherwise I would remove the pickups.

Bob

gunrunnerjohn posted:

I found that MTH, for reasons I can only imagine, wired the green and red front/rear markers in parallel!  OOPS!  

Wow!  That's a pretty basic goof.

Fully aware of the issues of running LEDs in parallel, I added headlights and tail lights in some 1:48 vehicles.  My supply voltage was not high enough to supply the 6 LEDs in series (the cars had double headlights).  So I ran 2 white LEDs in series with a red LED on each side and then connected the strings parallel.   This was put in series with a CL2 LED driver.  As you said, if the tolerances are tight you can get away with it.  All the white and the red LEDs were from single batches.   I actually got lucky and the first 4 cars were fine.   Then #5 failed.  Over the next few months something interesting happened.  2 of the first 4 cars had one string of lights fail (all the voltage goes to the other string).  Clearly not a good longterm strategy.  I'll use a CL2 in series with each string in the future.

John

Any thoughts whether the rear headlight circuit on the board in the lead unit might be an easy fix?  If not, I'll supply the headlight and number board in the trailing unit off of track power.

Bob

You can run them in parallel if you add in a series resistor to each string.  As long as the resistor drops more voltage than the difference between the lowest voltage LED string and the highest voltage LED string, they will light.  If you have limited current, you'll have to adjust the resistors to balance the lighting.

gunrunnerjohn posted:

So does Lionel and MTH.

I just got a RailKing subway set in for repair, a lot of the green marker lights didn't work for some reason.  Of the four cars, one worked perfectly, the other three all had issues.  When I opened them up, I found that MTH, for reasons I can only imagine, wired the green and red front/rear markers in parallel!  OOPS!  The green LED's run at a higher voltage than the red ones, so unless you got really lucky with the variances in the specifications, you didn't get green markers!  The difference isn't much, just .2 volts, just enough to screw things up. 

 

Model number please?  Is this PS-3 or PS-2?  G

I got it in a box without any ID, but it appears to be the 30-20301-1 PS/3 set. The guy bought it used, so he didn't have any warranty, though it's pretty new from the ship date. I was a bit surprised to see the sub-standard workmanship. One car was totally shorted as they had assembled the little P/S board incorrectly and it was wedged into the frame and melted the wiring. The engine and two cars needed a resistor tweak to allow all the lights to light.

Have to keep a lookout.  Is it possible it was modified?  G

I don't think so, the cars obviously had never been opened, and there was no sign that anything was tampered with.  You can almost always tell when you're opening a "factory fresh" unit, the screws are REALLY tight.   There would be no reason to modify them not to work I would imagine.