Loco does not respond to throttle

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michael leventoff

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My locos run at full throttle and do not stop with the throttle on off or respond to brake. I have a USA 10 amp transformer and USA diesel loco with 4 heavyweight cars. I also tried my extra MRC transformer and another Aristocraft diesel loco and have same problem. The trains were running normally and took off at full speed with the throttle on off. I had to turn off transformer to stop train. The layout has been running correctly for over a year. Any ideas
Michael
 
If it's an analogue DC controller, then I'd suspect that the controller is faulty.... can you put a voltmeter across the output terminals of the controller/powerpack, and see if it varies when you turn the control knob? If that is showing full voltage all the time, then whatever the knob is connected to (probably an electronic speed control circuit) is not working.....

Jon.
 
I looked at display on the transformer and it goes to 0 when I turn throttle to off but when I test with volt meter the amps are constant with the throttle on off and when it is turned up all the way
 
Two different transformer/controllers with the same symptom? That's strange, I would think you have a wiring problem perhaps the track is connected to an accessory out-put?
 
michael leventoff said:
I looked at display on the transformer and it goes to 0 when I turn throttle to off but when I test with volt meter the amps are constant with the throttle on off and when it is turned up all the way
Click to expand...

Not 100% sure I follow this??

Your power-supply has a output display, or you had your meter across the output?
If the former, then either you have short from an auxiliary supply somewhere, or a faulty supply.
If the latter, then the transformer is fine, and there is a short from an auxiliary feed somewhere further towards the layout.

You say it was running normally? - Has anything changed, been added, or moved about? - If so, look over that carefully.

I would start at the beginning:

Disconnect track supply. Switch on. Does a loco immediately move, with power at 'zero'. - If so fault is with whatever other supply(s) are connected to the layout.

Put meter across transformer output. - Zero on meter, with zero on controller? - If it shows volts, faulty controller.
If zero on meter, turn-up controller and see if voltmeter also rises. - This proves transformer / control is OK.

The above tests should prove either a different supply is causing the problem, or a fault in your transformer / controller.

Hope that helps?
PhilP.
PS> Let us know the result, and where the fault is, even if it turns out to be a 'silly' you have done. - We all do it.
 
The accessories,ac, is not hooked up with the 2nd transformer. I did not make any changes to layout. I removed loco from layout. The 4 USA heavyweight cars have interior lights. The interior lights are very bright. They are much brighter than normal since I only run the trains at half throttle. I checked tracks to see if any objects that don't belong. I also tried 3 different locos, same problem
 
As PhilP says, disconnect from the track and measure the output voltage with a meter as you move the throttle. If it's on all the time then the unit has a fault and needs servicing/replacing.

[edit]
You didn't confirm if this DC or DCC?
[/edit]
 
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replaced my USA 10 amp which was running normally with my extra MRC unit and had same problem with both.I have had chronic problems with the MRC units.I know the Aristo and USA diesels I am using use more power than the LGB diesels I run with other part of layout. Both are completely separate and use separate power supplies and the other runs normally.
1. I removed AC connection so I know problem is not there.
2. I checked MRC unit with voltage meter. With unit on low and high and voltage meter had the same reading., despite different reading on the display on MRC unit. The lights on my USA heavyweight cars are very bright with transformer on low and on high
3. I checked the tracks for objects that may cause shorts.
4. I broke the layout into sections and had the same problem with both sections. The second section has a jumper from 1st.
 
Just to be clear, you mention USA and MRC "transformers"? Transformer is usually the separate hardware box that converts mains voltage to low voltage and can then supply power to a controller or throttle unit which varies speed and direction. If the transformer and throttle are in the same box it's often known as a PowerPack.

So... are you saying you have USA and MRC PowerPacks and both have the same problem, or are you simply trying different transformers to feed the same throttle unit?

If you mean the former it seems very odd indeed that two different powerpacks would both fail the same way. Have you disconnected completely from the track and tested the output of each powerpack as we've suggested (not just switched off sections of your layout)?

On the other hand if you haven't changed the throttle, just tried a different transformer, then that would seem to indicate a fault with the throttle unit.
 
ntpntpntp said:
Just to be clear, you mention USA and MRC "transformers"? Transformer is usually the separate hardware box that converts mains voltage to low voltage and can then supply power to a controller or throttle unit which varies speed and direction. If the transformer and throttle are in the same box it's often known as a PowerPack.

So... are you saying you have USA and MRC PowerPacks and both have the same problem, or are you simply trying different transformers to feed the same throttle unit?

If you mean the former it seems very odd indeed that two different powerpacks would both fail the same way. Have you disconnected completely from the track and tested the output of each powerpack as we've suggested (not just switched off sections of your layout)?

On the other hand if you haven't changed the throttle, just tried a different transformer, then that would seem to indicate a fault with the throttle unit.
Click to expand...
I have the same problem with both power packs. I have had chronic problems with the MRC units which is why I don't use them
 
If its analogue it has to be the controller, that is unless you have just invented perpetual motion, in which case I would be very careful as the petrol companies (amongst others) may put a contract out on you

images.jpg
 
OK so same problem with a USA 10 amp powerpack and with an MRC powerpack which you tried instead? I ask again, you've meter-tested both of these powerpacks whilst NOT CONNECTED to your layout in any way? Sorry to labour the point but it seems difficult to believe that two different brands of powerpack would both fail in exactly the same way.
 
Lets take this back to basics. Nothing new here - just re-iterating what has already been said.
You need to have to hand one of your powerpack, your test meter and a plug socket. Nothing else. No trains, no track, no wires, no nothing. Just a plug socket, the power pack and your meter. Three items.

Set your controller to 0 or off or centered or stop - whatever.
Plug it in and switch it on
Test the output at the terminals you use to connect to the track.

Tell us the reading on the meter.

Turn the controller to full, test the out put again and tell us the reading.

Now try the other power pack - do the same tests. tell us the results

You have not got anything else in the test have you? No transformer, to loco, no rails. Just a plug socket, the powerpack and your test meter.

Sorry to make this sound simplistic but we seem to be missing something obvious here - or else you do have two identical faults - which seems unlikely,
 
I TRIED TO use the volt meter but could not get a reading from just the power pack, no matter what the setting. I thought it might be the jumper wires so I disconnected them and still same problem.
 
I only have the MRC power pack at home. I sent the USA power pack to get repaired. I called USA trains and they said this is a common problem and they would fix it. I kept the MRC as extra but always had problems getting it to work
 
It gets more weird. You cant find an output but your trains go full pelt.

Does your meter work - test it on a battery.
 
stockers said:
Does your meter work - test it on a battery.
Click to expand...
... make sure to set the meter to DC volts (not amps - you mentioned amps in an earlier post Michael?)
 
O
stockers said:
Lets take this back to basics. Nothing new here - just re-iterating what has already been said.
You need to have to hand one of your powerpack, your test meter and a plug socket. Nothing else. No trains, no track, no wires, no nothing. Just a plug socket, the power pack and your meter. Three items.

Set your controller to 0 or off or centered or stop - whatever.
Plug it in and switch it on
Test the output at the terminals you use to connect to the track.

Tell us the reading on the meter.

Turn the controller to full, test the out put again and tell us the reading.

Now try the other power pack - do the same tests. tell us the results

You have not got anything else in the test have you? No transformer, to loco, no rails. Just a plug socket, the powerpack and your test meter.

Sorry to make this sound simplistic but we seem to be missing something obvious here - or else you do have two identical faults - which seems unlikely,
Click to expand...
 
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