Multimeter vs TPC help.

Disconnect everything from the track and measure across the center rail and outside rails.  If you still have a short, you need to track it down.  Trying to diagnose this with equipment connected is going to be difficult.

I did that, but I went back and did it again. I took off the wire from the track out terminals from both TPC and the reading goes away on the track 1 and 2. When I measure each one of those wires to ground both read 4 ohms when the meter is set to X10 on the ohm scale. To me it appears the 4 ohms is coming directly from the track out terminals of the TPC. Sort of like the TPC should read 4 ohms output from those terminals??? I also did this was a different multimeter and got the same readings.

Larry

Are you saying the 4 ohms is across the TPC or across the track with nothing at all connected to the track? 

If the track is not connected to anything (and there are no track powered switches involved), you should get very high resistance between the center and outside rails.

I've never actually measured directly to the terminals of the TPC, as long as they're working, it never occurs to me to do so.

The 4 ohms is across the track out terminals A U on the TPC. It's not on the track until I connect the TPC A U track out wires to the track.

"If the track is not connected to anything (and there are no track powered switches involved), you should get very high resistance between the center and outside rails."

John I don't understand that?? Why would I meter any resistance if nothing is connected to the track. Shouldn't it read none. I confused again.

Larry

If ohm reading track center to outside rail you should read infinity ohms or Open.

a "none" reading is a short. As in less than your 4 ohms.

I have no input on that issue as I don't have a TPC to check.

Thanks Russell

I think I'm referring to it backwards. If the meter needle don't move no short, if it swings all the to the right ..dead short. Which is farther than my 4 ohms reading from the TPC

Larry

Right, for the open track, you should get no reading, i.e. infinity.  I just checked a new TPC-300, I get 42 ohms across the A and U terminals.  That is connected to nothing, right out of the box.

Well that's good news. I just see a 4 but, I can see where I should read 42, even with both my mickey mouse meters. Everything is working fine. I have run conventional trains today testing with the CAB 1, but not TMCC with the CAB 1  yet. I appreciate the help.

One could think I'm trying for the PITA award this month with all this new stuff I'm installing and asking questions about . And, I haven't taken the Legacy base out of the box yet.

Larry

Also,  Russell thanks for your feed back as well

Legacy is a piece of cake, no questions allowed on that installation!

I HOPE!