modern ZW amp/volt meter

You are using the wrong meter. Lionel made two volt meters. 14077 is the model designed for postwar zw. 14002 is for the modern zw using power bricks.

I've never worked with the 14002, but an amp is an amp, & looking through the manual, it is connected the same as the 14077, and should behave the same electrically, and work just as well as a stand-alone. I would try the 14002 on an original ZW to confirm that it works before getting into the stand-alone project too far, and confirm that you have made all of the necessary connections, because the current readings are taken from the top row of "U" posts.

I always thought that the only difference between the old and new meters was the hole in the back for a button to initate the programming on the new version.

Thanks for the comments. As I mentioned earlier, this amp/volt unit does work on my modern ZW, it displays amps and volts fine. I am wiring it in same way to my old postwar ZW, but cannot get the amps to display. The reason I am attempting to use it on my old ZW is because my modern ZW inner bracket handle supports have broken twice. The last time I made a replacement bracket myself using some UHMW, and while it does work I am trying to use that transformer for accessory power and not have to adjust the handles as much in an attempt to prevent the handle supports from breaking in the future. 

They were two different meters if I  recall right ,one worked only with the new ZWs the other worked with the older iron core ZWs. Doesn't look like they are inter changeable.

Vic58 posted:

Thanks for the comments. As I mentioned earlier, this amp/volt unit does work on my modern ZW, it displays amps and volts fine. I am wiring it in same way to my old postwar ZW, but cannot get the amps to display...

How about installing it ON the postwar ZW... that would be the real test.

I would try installing directly on my postwar ZW but the terminal spacing is different. Just to test, I have hooked it up to my modern ZW without being attached directly to the case, just using wires to make the electrical connections. It does work properly and displays amps. Try it back to the postwar ZW, volts but no amps. Maybe the modern ZW is providing DC to power the display, which the postwar ZW would not.

Vic58 posted:

I would try installing directly on my postwar ZW but the terminal spacing is different.

OK, so that is the difference. I've never had the 14002 in hand, did not know that.

There is no DC component in the ZW except for the offset in conventional mode with the whistle/bell activation on A & D.

I know the 14077 works with PM-1 PowerMasters and modern phase-modulated transformers, as I have done what you are doing and used the meter as a stand-alone, so there is no reason the 14002 needs to be different in this manner.

Just to be sure this is not an issue, you are aware that the 4 "U" posts on the meter are not really "common" anymore once connected? They will act like common, but if connected to a common ground layout, all four, they will each display 25% of the total current draw from the connected transformer(s). If you connect just one "U" to the layout, it will display total amperage in just the one display window corresponding to the (A-B-C-D) post below it.

Rob

 I have hand tremors to the extent that I have difficulty connecting charger clamps to a car battery. Connecting and testing anything live these days, even low voltage or current is off the table. I take your word for all railpower assessments.