Grounding Problem with MTH Railking FP45......

Have you removed the shell and looked for any pinched wires?  I have several of these engines but never had this issue. The sparking wheels is what makes me think there is a shorted wire.

Hi SPSF......I have not removed the shell. The engine runs well on regular tubular track. It just stalls when running at low speeds across the switches. And the sparking from the wheels occurs when I run the engine at higher speeds across the switch; which led me to believe the engine is breaking contact with Ground from the outer rail.

But I will remove the shell and see if there's anything that looks funny.

Thanks.....

It could be the solder connection of the ground on the truck and the wire is loose.

What is Lionel Hi-Rail track?

Hi Carl......sorry......must've been a brain fart. I meant tubular track . And I need to pop the shell off of the engine and check things out. That's on my list of things to do today......

If you have a continuity meter check out at the work bench what outside wheels are actually  common to each other .

 With traction tires and 2/3 rail engines the outside rail pick up can be a problem...( unlike our old Lionel trains  where every outside wheel  picked up the common)

It is possible if both pickups hit dead spots.  Does it do it at all speeds or just slow?

To determine if you have a pickup wire issue.  Place 3" of electrical tape on the center rail of a piece of straight track.  Drive train over it slowly.  If the train stops and shuts down, the PICKUP NOT on the tape is not connected to the power wire for the engine.  Trouble shoot and repair.

The other problem could be a bad ground and you need to check each truck ground to the chassis.  If not near 0 ohms you may have ground wire issue, or the coating on the black ground wire terminal screws is too thick. Scrape coating off the bottom of the screw head or change it to a nickel screw.  G

Hi Gregg.....sorry for the delay responding. I do have a continuity tester. Haven't used it in quite a while.....will have to hunt it down .

The engine definitely stalls at slow speeds (5 - 10 scale mph) dropping into shut down. When I blast the engine through the turnouts as say 50 - 60 scale mph, the engine makes it through the switches; but there is an occasional really quick hesitation that is visible.

Thanks for providing some techniques for narrowing in on the problem....I'm really interested to see the results of these tests.

BTW, this FP45 is a PS3 engine......should've mentioned that earlier. Not sure if that makes a difference. And I'm running Rev. L TIUs with v6.0 software all around. And all the switches are powered via the external power tap at 14 - 16 volts.

Thanks!

Check to see if the pickup rollers are high centered on the switch lifting the outer wheels off the rail slightly and breaking the ground.

I had a PS3 GP9 that did this. I solved the problem by replacing the rollers with smaller diameter ones.

Hope this helps.

Well Guys......I finally pulled the shell off and......I seriously can't believe my eyes! There appears to be a connection that is SNAPPED OFF of one of the power trucks! I'm including 2 pictures for comparison.

Here's a pic of the front power truck which appears to have 2 connections; one for a Red wire and one for a Black wire. Each is held in place by it's own screw.

Here's the connection for the back power truck. As you can see.....the connector to the truck for the Black wire is completely snapped off! And the heat shrink tubing appears to be chaffed up pretty well too.

This appears to be a pretty easy fix. I just need to get the connector (looks like its 'L'-shaped), solder the wire onto the connector, add new heat shrink tubing and screw it to the power truck.

But what's weird is....this engine has never, ever been dropped. Not sure how something like this could just snap off.

Anybody out there know what the part number would be for that 'L' connector? The engine is a RailKing 30-20154-1.

Ah....never mind about the part number....it looks like its just a 22-20ga crimp-on ring connector.  I thought it was something special......

Great you found the problem.   Looks like a "not too hard of a  fix" and I hope there's enough slack in the wire to allow the truck to swing freely.

Hey Gregg.....I had to remove 2 zip ties to get a bit more slack in the wire. Once I did that, I had enough wire for free movement of the power truck. I also had to put new zip ties back on the wire bundles. One bundle was wrapped with a heat proof "blanket" because it was close to the circuit board's heat sink.

Just got through testing the engine.....it glides though the switches effortlessly ......no stalls. I just don't get how that connection broke......weird. 

And a big 'THANKS" to everyone for all your suggestions. I would have never guessed the problem was caused by a broken connection!

PS. As part of this problem, I started "tuning" all my Lionel 072 switches where the center rail is significantly higher that the outer rails. It's a pretty easy process that does not require "a hammer". This will be a separate post with pictures.

If you noticed, when the truck turns it will tug on the wire. When there is not enough slack, it gets pulled. The pulling can flex the connector until it breaks.

On engines with low hours, I suspect that it is just a manufacturing/assembly error that damaged the connector.

No matter, one just has to find it and repair it.

Thanks for showing the cause and the solution. It's helps others later when they find this post.

Put some hours on that engine!

Hi Carl........Thanks for the kind words! I do like to share what info I can find or develop it as I go along.

Already working on putting hours on that engine .