MTH QSI DCRU Reverse Problem

Is voltage going to zero? What transformer are you using?  G

I am using a Lionel CW80 transformer. I am turning power completely off

Have you checked your output voltage with a VOM when the throttle is down to zero? A lot of transformers leak voltage when they are throttled down; that could be enough to keep your DCRU from tripping. That's a very common problem with Williams reverse units. 

Does it help to put one or two lighted cars on the track?

 

Some of the modern transformers will not go to zero without a load on them.

I agree with RoyBoy. I have several early MTH QSI-equipped locos and I had to wire a light bulb to each output of my Z4000 transformer to present a load to it so the QSI reverse units would cycle properly.

As I recall, the instructions called for a lighted car or even a lighted bumper connected to the track to give it the load the loco needs.

TJ

Thanks everyone! I wired a scrap lightbulb assembly to the track and that did the trick.

The CW-80 is the issue, it needs the load to properly adjust voltage.  That is why when you have the lighted engine on the track the reverse unit worked fine.  Easy fix.  G