Help with DCS, DB, MRC 8and PM 42 shorting in REV : LUSENET : Wiring for DCC : One Thread

This used to work. All kinds of wires have been changed around with no help. I need the 8 amp as I am running trains with 4 power units each.

With the DCS 100, DB 150 MRC 8, and PM 42 on line the engine short going in and out both way thru the revers loops. The DCS and DB are in sync. Going to 00 and speed 99 on my DT 400R. LED will not light going to A to A or B to B on the REV. LED will light in the REV and on the main.

I have the DCS going into a MRC power station 8. The DB go to a PM 42 set up for 4 REV loops. Only 2 wired up now. The DCS has 16.72 volts in and 15.12 out to the MRC 8 and the MRC has 15.95 out. The DB has 16.73 in and 15.57 and the REV one has 15.26 and the other 15.05 at the track.

Cases grounded together DB, DCS, MRC 8, and PM 42 all going to a water pipe. On the DB has config A jumper to GD; B jumper to GD.

I turn the DCS on first then the DB.

DCS rail A and B go into a MRC power station 8 DCC in side. The other 2 wires to the main tracks. A PS 515 power both the DCS and DB. The DCS Loconet A go to the A on the DB. B on the DCS go to a UR 91 and a UP5. The DB on the B side Loconet also go to a UR 91.

Now taken the MRC 8 out of the system the engine will go in and out the REV's OK. The LED will light going to A to A and B to B on one end of the REV loop. But I cannot run all of trains without over loading.

REv's gaps check good with a meter.

I did installed a MRC AD350, Digitax AR1, and a Tony's PS REV all new and was still getting a short with them when the engine came into or left the REV loop. The LED would light going to A to A or B to B on one end of the REV. The AD350 and AR1 went from REV to main from the track. The PS REV received it power from the DB 150. Changed rail A and B around on the DB and no change. The MRC 8 was NOT on line for the above or the PM 42.

Some time turn the power on the DT400R will not come up with the correct engine number set in them. Not all of them. Unplug them and then the correct number will come up.

I used to have 2 Broadway E7's running with no problem then I start having trouble turn the power on and now the REV's loop shorting.

Thank for any help. Dennis

-- Dennis Ray (, October 12, 2004


More info Going into the REV short and going out OK. Opposite direction in OK and short going out. DB 150 op sw 02 T Booster only override normal is T op sw 03 C Auto reversing is T Configa A to ground (not case)

Going to 00 and 99 power both DSC and DB in sync both red/green.

LED with not light going to A to A or B to B ether end of REV. Light in the REV A to B and on the main. Now with 00 and 99 power with the LED on the main or REV the LED is bright but hitting the Revers on the DT400R the LED go dim. Swap rails on the main and in the REV the LED will swap dim to bright.

The engine was shorting in all direction but changing around wires today I got it to work half way.

Still need some help. Thanks

-- Dennis Ray (, October 12, 2004.

It is working now. Add a new power district in front of the REV loop. Add 2 wires from the DCC in put on the MRC8 to the new power district. LED light now going A to A and B to B on one end of the REV loop. Now I need to do the other 3 loops the same way. I have been working on this problem for over 2 months.

-- Dennis Ray (, October 14, 2004.

Auto-Reverse Rules 1. Auto-reverse section should be longer than the whole train. (or at least those parts with metal wheels and pick-up trucks) Many discussions...Few exceptions that work 100% of the time. 2. Auto-reverse sections must be flanked at each entrance/exit by track that does not auto-reverse. The 'fixed' polarity track section must be longer than the longest truck-truck span of all locos or passenger cars with metal wheels and pick-up type trucks.


-- Don Vollrath (, October 15, 2004.

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