Post MTH service issue-help

Is it a PS3   2/3 rail?   Product number might help here.

This is a MTH Premier PS3 3 rail. From 2014 catalog.

Make sure your tether is plugged in well. 

Check the tender.  There should be a wire from an axle wiper to frame.  Decapod had same issue, until we installed these wires.

I have checked the tether and it is secure. Interesting, that except for the lighting issue, this engine ran very well before being serviced. Also, stalling on fastrack switch happens when tender is on switch which goes along with what RJR has suggested. All of my other engines activate crossing gates with the first set of wheels. When this engine crosses, nothing happens until engine is almost through.

CALL THE SERVICE DEPT AND LET THEM KNOW, THEY MAY BE ABLE TO WALK YOU THROUGH. IF ALL ELSE FAILS SEND IT BACK.

HAVE YOU TRIED A FACTORY RESET WHICH CAN BE DONE IN CONVENTIONAL OR DCS MODES

Under certain conditions of track level, and going over non-derailing switches which have an outside rail insulated, the R-K Decapods would stop when going slowly.  I traced it to the fact that between a long wheelbase, traction tires, and insulated rear drivers, loco would lose ground & stop when going very slow.  Solution was the wire I mentioned above.  Normally, the trailing truck provides a ground but without the trailing truck, loco depends on tender.  The Decapods did not hjave the wire I mentioned.

One of the resident gurus poo-pooed by problem until he encountered it.  He also was shocked how I discovered it:  when loco was stalled, I slipped a fine screwdriver under a driver and loco powered up.

I am starting to think that this issue is being caused by the power pickups and not by anything done while at MTH service. I recall a post where Barry mentioned adding pickups to the tender for a similar problem. This issue seems to be associated mostly with insulated track sections on switches and gate crossing. RJR, did you add the tender wire yourself?

Yes, real simple.  There already was a wiper, with nothing connected to it.  I ran a wire from that to the tender frame, under one of the existing crew heads.  Center rail pickups were not a problem.

There is more to the loss of power when going slow through switches. It can be do to the geometry of the wheels and the pickups.

I have an MTH PS3 City of Denver with an unusual wheel arrangement. The cars are supported by a funny little four wheel round pedestal with only the observation car itself having any support from fixed wheels in the back. The engine clips into one of the little round truck device in the back and only has a single set of attached drive wheels with a single central pickup. When it goes through an O31 switch from the curve section to the single outlet straight section the center pickup shorts out the track, causing arcs and sparks and stalling if going too slow. Running in the opposite direction is no problem nor is it a problem running through several O72 switches in either direction.

MTH does not pay enough attention to details like the truck and pickup geometry and/or their switch design is not sophisticated enough. If this is known to them (and I notified them with no response form them) that this toy train can not run through certain switches you would think they would include a notice to that effect in the box. Under certain condition (like track on a rug) the arcs could be big enough to cause a fire.

In addition I have seen some of my engines when running extremely slowly stall through switches. Obviously something is loosing contact with the track power. Since I rarely run that slowly I have not pursued the solution to the problem. In the above City of Denver case, it also had flickering lights until I added a set of little harnesses to tie all the round support pedestal sections electrically together. No more flashing lights. I relegate it to my outer loop which has no arcs and sparks problem.

If you have not had one of these MTH PS3 engines open you are in for a surprise. It is a scramble of wires running every which way with some connections made with twist on connectors. For the money you would think MTH would find a better way to route wiring than just point to point all over the place. In the MTH repair it is possible they broke a wire connection somewhere. I have not sent anything to them for repair because I keep reading on these pages of many multiple trips required to get the MTH engine working correctly. I have no confidence in their ability to do the repair right the first time.

LDBennett

Need your specific model # to help.  Is this a 2 rail 3 rail model with a switch?

Here are some thing that you said the require a review.

You said it ran fine on this layout before it went in.  So this is not a geometry issue if that is true.

You also say it runs fine in one direction but not the other.  That indicates it is an issue picking up outside rail ground and not center rail.

If these statements are not true, than all bets off.

First, clean wheels and pickups well.  Second check continuity between pickup rollers on the bench.  Then connect tender to engine and with engine/tender on side check continuity between engine frame and tender frame.  It should be zero resistance.

Is the drawbar ground spring attached?  A picture or two could help along with model #.  G

GGG - thanks for your well thought reply. Once I thought about it, the engine had run great on a loop of MTH realtrak with only one MTH switch. The issue that it is having now is with Lionel Fastrack switches and crossing gate. Seems to be associated with the insulated sections. The model number is 20-3562-1. It has the 2/3 switch but it is set to 3 rail.

One new Premier Diesel, with the 2/3 rail switch, failed out of the box. It was that the 2/3 switch did not work (no continuity through contacts of switch). Since I'll never have 2 rail I jumpered from the 3 rail side of the switch to the common terminal by a soldered wire and left the switch in the 3 rail position. All is fine now. Another MTH electrical problem that should have been caught at the factory so they obviously don't do a thorough testing of new products before shipment.

LDBennett

Speperak

What GGG said.

Also my observations

I have mostly PS3 MTH2/3 rail engines, and have this problem when running slow though a turnout (Ross), it is a ground problem, working fine one way and not the other is the clue.on diesels I fixed this problem by installing three rail wheel sets that where not insulated. I asked MTH service if I could do this and the tech said yes as long as it stays in the three rail mode. On steam I am still trying to figure it out. I will try what RJR said.

Thank you RJR.

Doesn't seem to happen to PS2 2/3 rail engines.

clem 

LDBennett, I plan to check continuity of pickups and frame as suggested by GGG and now will check 2/3 switch also. thanks.  I have also read about placing a jumper on outside rail of switch to the next piece of track. Do you think that would help? Clem, I was hoping that when I upgrade to Ross switches these problems would go away but does not sound like they will. I am going to speak to mth tech about engine not activating crossing gate and then start testing a few ideas. Not sure how tender wiper figures in, but if wiring it to frame will help, sounds like a simple solution?? The problem with the crossing gate is really strange. All of my other engines and cars trip that thing right away, but not this engine.

The switches usually have an anti-derailment feature that makes the switch change to allow a train through a switch that is set in the wrong direction. It does that with a short section of isolated track from the points area to the two different directional tracks. The outside rail gets shorted across to the isolated track which activates the switch to change. If the right side of the engine's wheels are not electrically connected to the left side wheels then the connection for the anti-derailment feature might not work, the isolated tract section for signals might not work or the engine may stall in the switch when traveling slow.

The 2/3 switch is suppose to connect the wheels together in a Premier engine when in the "3" state. could it be you 2/3 switch is bad like mine was???

LDBennett

This is because your engine has isolated wheels to be able to run in 2 rail.  So your not triggering a ground connection.  G

speperak:

Be careful what you are jumpering because on some manufactures switches those two section at the inside of the V of the switch must be isolated. Jumpering them to the adjacent track will possible burn out the switch motor. On my MTH RealTrax I had to shorten those rails in order to isolate them as MTH made them too long.

I really think the problem is in the engine and possible the 2/3 rail switch (??).

LDBennett

LDBennett and GGG, I really appreciate your thoughts on this issue. GGG, is this likely to be the 2/3 swithch? Does this engine ground across the drawbar to the tender wiper?

We saw this problem with the PS-3 Premier VO-1000 diesels with 3-2 wheels.  The 3 rail/2 rail switch was not wired properly, and in 3 rail mode it didn't connect the wheels and both sides together.

Stuart

Good morning Stuart

Could you describe or have a diagram of the proper wiring to the 2/3 rail switch? so I can check my Diesels.

Clem k

My 2/3 switch had contacts internally that were no connecting in the "3" position so it was a switch component part failure, not a wiring problem. But as messy as the wiring is internally for these engines, wiring mistakes during assembly are highly possible, in my opinion. With MTH, any failure is possible!

LDBennett

Hi Clem,

The engine was service by MTH, so I don't know what they changed to correct the problem.

Sorry,

Stuart