RK F3 short

Engine ID# always helpful. You have a tach tape, so it has PS2 or PS3. First try spinning both flywheels by hand. There should be no resistance. If you feel resistance, check nothing is bound up in the trucks.

Engine/number board is #24 Santa Fe.  There is a sticker and the sticker on the bottom of the frame that indicates PS2 Passenger.

I'm guessing the engine is from a R-T-R Passenger Set and maybe it wasn't originally SF #24 and the shell was swapped.  If I look up 30rtr13260i.pdf on the MTH website the exploded diagram looks like the engine in question, but it does not show SF#24 as an option.

Nothing seems to be bound.

My impression is, nothing in theory "wrong" with the engine. Losing power is NOT "shorting"- completely different things.

Your video is showing the test performed on Atlas track with blackened center rail. As I've said before, I have personally seen loss of power with certain types of pickup rollers (the roller material) with that type of track in that condition.

Highly suggest basic power test 101- use alligator leads to connect directly to the PS2 power wiring inside the engine. If it works this way- then the answer is clean your wheels and inspect pickup rollers and wiring and consider interaction and cleaning of the blackened 3rd rail.

Again, the red and black bundles of wires are the power connection points for the power entry into the board under the yellow wire nuts.

I use something like these in conjunction with a Z500 transformer and newer Zcontroller

Also, I'm not saying you have to jump straight to clipping alligator leads.

The thing is, from the first post, the symptoms are NOT a short. They are indicative of an engine with either dirty wheels and rollers, or dirty track resulting in intermittent power getting to the engine.

I also realize everyone is at different levels in the learning game, but there has to be a baseline minimum common language when troubleshooting.

A short is a load that trips the breaker or safety protection on a transformer and draws heavy current.

A loss of power or open circuit- example engine just intermittently loosing all power and lights- entirely different scenario- not in the same ballpark.

Hi I notice it only powers up for a few seconds and then headlight goes off looks like a loss of power or ps 2 3 volt board is seeing an over current which causes the board to shut down automatically immediately! have you checked for dirty wheels and or dirty track! what is the current draw when you power it up without starting it up? should be around .3 amps or less!

Alan

Thanks @Vernon Barry. Using test leads directly to the red and black wires, while on rollers, indicated that the rear motor with the tach tape was spinning freely and without issue.  The front motor, however was intermittent, jerky, and kept hanging.  When the front hangs, if I spun the flywheel by hand, I could get it to maintain power, but it is no where as smooth as the rear motor.

If it’s losing power, check continuity between both rollers, between the wheels between both trucks and the wheels to the truck block or ground screw on the black ground wire. Paint on the truck block can sometimes limit continuity between the axle bearing and the truck block.  Just takes a bit of detective work.

@VADarthDad posted:

Thanks @Vernon Barry. Using test leads directly to the red and black wires, while on rollers, indicated that the rear motor with the tach tape was spinning freely and without issue.  The front motor, however was intermittent, jerky, and kept hanging.  When the front hangs, if I spun the flywheel by hand, I could get it to maintain power, but it is no where as smooth as the rear motor.

Expected. The motors are BOTH getting the same voltage at the same time. One has a tachometer feedback, one does not. When you slow the non feedback motor, nothing voltage wise changes, when you slow the tach feedback driven motor then BOTH see an increase in voltage.

Thoroughly clean the wheels with out traction tires.  Make sure pickups look ok and clean them with an electrical cleaner/lub.  Make sure track power wires good, screws tight.  G

You guys are amazing. Wheels and rollers looked perfect.  I cleaned them anyway. Wheels were much dirtier than they looked.  Started up and runs fine. No issues.  Thanks.