Passenger car parked across two different isolated blocks?

Yep. I did this with a dummy F 3. It 2 different potentials. And if out of phase it could be a pretty substantial difference. 

Thanks for the quick clarification Marty.

I'm using a pw zw one side is off the C output at 5 volts and the other side was off the D output at 15 volts.

This is the first time I ever tried to use block wiring maybe I should do more research before I proceed.  

Great to know!

the problem you could have is that the voltage will transfer between the blocks via the car if all the lights in the car are wired together. So block A could be off via the transformer but getting power via block B through the car.  Is this a total isolation, meaning all 3 rails, or just the center rail power?

Just the center rail is isolated. I just noticed I inadvertently wired both outside rails  for common. The passenger car is part of the LionChief Polar Express rtr set and the two rollers are wired together.

Matthew,

The commons are ok being on both rails. Dale H. had a way to manage this when running in conventional mode.  email him if you are.

Why do you have two different voltages in you are running LionChief.

Each power division should be the same voltage when running command or LionChief.

The problem is that the wire inside the passenger car is too small for the circuit protection in the transformer.  On a Post War ZW a ten amp fuse or circuit breaker should be added to each output. But this is only protection for #16 wire. The passenger car is probably wired with #24 wire and needs a much smaller fuse, maybe 3 amps.  The passenger car can not really have larger wire because of the flexibility needed in the wire that connects to the roller. The other option wound be to put a 3 amp fuse in any car or loco with rollers connected together with small wire. That way if a car was left across two different feeds set at different voltages, if the voltage difference was high enough to damage the wire, the fuse would blow and protect the wiring. The fuse needs to be in the wire that connects the two rollers.  It does not need to protect the lighting as this is a fixed load and the wire will have been designed to handle that load.  

When I wire with LED's in passenger cars, I put a low value PTC in between the pickups.  This protects them from derailments and still allows the lights to function.  For incandescent lights, a 1A PTC will work, and you don't have to take the car apart to replace a fuse.

I think the issue will also occur if for example one of the blocks is off and the other on with another draw on the off block.

I finally got back to the scene of the accident. When I noticed the smoldering passenger car I had just finished checking all the power feeds with my voltage meter and shut the power down immediately. The passenger car had been parked across the two Isolated tracks for about three minutes.

I had to pick up Theodore from the vet so I never got a chance to see if the track worked with the Isolated blocks until after dinner. It works great Running just the engine and tender with about 7 volts on the decline, 16 on the incline and the throttle on the remote set at about half power. There is some sparking when the engine crosses one of the gaps between isolated sections. I attribute that to dirty track. So tomorrow I'll clean all the track.

 Dare I try running the passenger cars as they are? Will there be any problems as long as I don't park a car across the two Isolated blocks?

I have to rewire the abandoned toy car so I guess I'm heading back to the LED lighting thread.

Gun Runner John: I have a feeling you'll be hearing from me.

Best regards all I appreciate all your input.

If you're heading for LED lighting, might as well run them until you do the conversion.   After all, you'll be in there rewiring anyway...

Start slow and work up steam.