Electro Couplers not opening

Well, it seems that a slight deficit in track voltage WILL affect coupler activation.  I found a few spots that were in the mid 16 v range so today I spent time running jumper wires. Now, I have a solid 17.9 - 18.0 everywhere.

So given that, NOW every coupler on every loco works flawlessly.

Apparently, my two recent trackside additions lowered the track voltage enough to cause the problems.

Well, I was actually going to suggest this, but you initially stated that they also didn't work where the track voltage was 18 volts, so I rejected that as the cause.

FWIW, I run with Lionel PowerHouse 180 transformers on my layout, and the actual measured voltage on the tracks is around 18.25 VAC everywhere with no load, and around 17.5 VAC when I have the Vision Line Big Boy with four smoke units working and pulling 30 cars.  I've never had any coupler, Legacy, TMCC, or MTH DCS fail to operate correctly here.  However, on my test bench, if I turn the voltage down to 15.5-16.0 VAC, I can get failures on some couplers.

I would point out that with no load I measure almost exactly the same voltage no matter where I check on my 140 foot mainline or any of the secondary loops.  If your 16.5 VAC & 18 VAC measurement was done with no load, that would suggest a possibly poor connection to drop that much voltage with no load.

Thank you GRJ. Yes, it’s a little confusing and I do think that a potential weak connection might have contributed to the issues.

It is interesting that yesterday the front couplers would fire but not the rears which make me suspect that the long engine (being on two different 10” sections of Fastrack) actually had two different voltages at each pickup due to the suspect poor connection? By tearing it down to add the jumpers today may have also fixed the poor connection?

I rechecked voltages this evening and had nothing less than 17.94 and several numbers over 18.1-18.2. All numbers before and after the jumper installs were with two Legacy diesels powered up with one pulling a fairly easy consist of 16 cars. With no load on the track all numbers everywhere were  ~18.2 this evening.

I currently run a single Powerhouse 180 on my 135’ of track that has one outer mainline of ~80’ and three sidings of ~17’ - 18’ each. I have seven 060 remote switches, two flashing grade crossings and a Railking Commercial Building (used cars) that are all track powered.

Lastly, I have five Legacy Diesel locomotives controlled by my Legacy 990 system. Do you think I should add another PH 180?

Thanks for the advice.

I run a 140 foot mainline folded dogbone, and it's powered by a single PH180 transformer.  I've had three trains (all with smoke) running at the same time on that mainline without any issues, the total measured amp draw was right at 6 amps, still some headroom for the 10A PH180 transformer.

If you do anything with power, I'd probably consider moving the accessories & switches to a separate power source.  If you haven't already done it, I'd also have independent switching for each siding so you can turn power off on each of them.

Thanks John. Great advice.