Smoke Fan Motor- Runs 2-3 seconds and quits- what could be the issue?

@hokie71 posted:

I checked a number of threads but did not see this issue addressed so hoping one of our experts has an idea.

I have a Lionel 6-11233 Legacy two truck shay with the standard (?) smoke fan motor. I run it conventional- I have not run this in a while and got the multiple flashing cab light warning.  Upon taking the smoke unit apart, when powered up, the fan runs for a few seconds and quits.  Based on my digital VOM, it appears the motor voltage drops to zero so I am guessing  it is not the motor - or perhaps there is an overcurrent sensor that cuts things off?  The heat resistor shows about 8 ohms.  Guidance appreciated on what / where to look next.  Thanks.

Looks like you've got a good start on troubleshooting this and have included helpful details about the issue.  Hopefully someone who's had experience with this type of issue can help you.  Since there hasn't been any other reply, I'd like to do you the favor of bumping this.

You need to disconnect the fan motor and measure the operating current at 5VDC.  It should be just a few milliamperes.  It may just need oil.  The Lionel board will shut down if an over current situation is detected.

Agree with @Jon G, seems like an over current scenario. You can lube it up and see if that brings the motor back in to spec (no guarantees it will last) . You can also  get a replacement 610-1154-130 motor, or it may be possible upgrade the motor with the MTH equivalent motor BE-000041.

Thanks for the responses and to Steve for the bump.  I will rig up a 5vdc power supply and see what I can measure.

I believe spec for the healthy motor is about 25ma. I think I recall from somewhere that the Lionel error detection is triggered around 40ma.

I just finished the test and at minimal transformer setting I had 7vdc.    At any rate, I ran the motor for about 5 minutes, hooked it back up to the locomotive and..... apparently I got some gunk out and all appears to be well.  I had sprayed some contact cleaner and some very light lube yesterday so perhaps running the motor for a while was a factor.   During this run in, I measured about  36ma but.... my meter has a single scale for DC and AC mA current so perhaps not to be trusted precisely.  Plus I only used a single diode for the DC supply so had half wave DC. 

Interesting factoid FWIW, I had an old DC fan motor in the parts bin from times past- it appears to use 90 ma when running so now I know why it was in the parts bin....

Thanks to all for the help, I plan to button it up, pray for the best, chalk this up to not running the fan for a year.... and buy a spare fan motor.  That thing seems to be in a ton of fan units.

The Lionel motors new from Lionel are somewhat all over the map, the range from around 28ma to 45ma, this is a sample of ten motors, five of each size, direct from Lionel.  I believe the Legacy smoke fan fault monitoring kicks on in the 60-80ma trigger range.

I believe this is where I got the 25ma I've been using number from years ago (pretty much straight from Lionel):

https://ogrforum.com/...14#29023675348469814

Using a cutoff of ~30ma, I've had a few DOA motors from Lionel and at the time seemed par for the course.

Yep, that's what they should test at.  However, if you test all the new short motors coming from Lionel, you won't find any that will be under about 35ma, and some are around 45ma.  The longer motors take a bit less current.

One of the short motors that measured at 45ma is in my Legacy Santa Fe Northern to replace a bad motor, it's working fine.  I don't know the exact threshold of the over-current indication, but it's obviously more than that.

From what Mike Reagan told me while at MTH, too much smoke fluid overflows into the smoke fan housing, seeps past the fan motor bearing and soaks the armature and brushes, which usually causes this demise.

@bmoran4 posted:

I believe this is where I got the 25ma I've been using number from years ago (pretty much straight from Lionel):

https://ogrforum.com/...14#29023675348469814

Using a cutoff of ~30ma, I've had a few DOA motors from Lionel and at the time seemed par for the course.

Wow, That is quite the thread from 2014!

@gunrunnerjohn posted:

The Lionel motors new from Lionel are somewhat all over the map, the range from around 28ma to 45ma, this is a sample of ten motors, five of each size, direct from Lionel.  I believe the Legacy smoke fan fault monitoring kicks on in the 60-80ma trigger range.

My sample of two is pretty much in this ball park.  The good one I got to work was at 36 ma and the one I pitched was at 90ma.

Yep, I believe 90ma would surely make the RCMC unhappy!