Lionel E-Unit Issues

[steve1946]

Hi,

I purchased a #736 and ran a bench test but the engine just sat there and buzzed!  Then I separated the e-unit from the frame and direct wired it.  The pawl moved up and down and the drum turned a complete 360 degrees several times.  The engine motor ran like a new one when I direct wired it but when the e-unit is solidly fastened to the frame and wired to the motor all it does is buzz!  I replaced the e-unit drum with a new one and cleaned the fingers but that didn't help.  I made sure the worm gear on the motor shaft was in proper alingment with the geared rear driver and that the wheels were quartered properly.  The chasis runs smothly and the side rods work perfectly but when power is applied all the e-unit does is buzz!  Does anyone have any thoughts on a troublesome e-unit?

 

Thanks,

 

Steve

 

[tinplatacis]

Do the fingers make contact with the drum?

[steve1946]

Yes, the fingers are aligned perfectly with the drum. I also cleaned them well with a non-scratch green scouring pad.

[BigAl 956]

Not sure what you mean by all it does is buzz? When turned on most e-units buzz. Does the plunger engage and stay up until power is interrupted?

[steve1946]

Bigal,

When bench testing and holding the e-unit in front of me I had one transformer lead on the coil and touched the other transformer lead on the e-unit case.  The plunger would lift up and turn the drum and drop down when I released the power.  The e-unit would make its normal clicking sound.  When the e-unit is mounted in the frame and the frame is on the track all the e-unit does is buzz when transformer power is applied!  As far as I can tell the motor is making no noise at all.

 

[rtraincollector]

If it works out of the engine fine but won't work in the engine to me sounds like you have something grounding ( shorting ) to the frame. So it could be another wire doing so. Check your wires good. 

[cwburfle]

IF the e-unit works when not installed, and just buzzes when installed (plunger does not go up), then there is an obstruction stopping the plunger from rising. Most simple: the mounting screw is too long and is stopping the plunger from going up. Maybe the pin that attaches the pawl to the plungers is rubbing against the bracket. Maybe a wire is out of place and is fouling the plunger/pawl. I have seen all these things.

[steve1946]

I appreciate the feedback.  Here is what I know for sure.  The motor works when hotwired.  The e-unit works when hotwired.  When power is applied plunger goes up and rotates the drum, power off the plunger drops.  When the e-unit is properly installed in the frame and wired to the motor all I get is a buzz from the e-unit.  There is no continuity from the wire coming from the collector to where it attaches to the e-unit solder lug. Therefore I believe that I am not getting power from the track to the motor and since the motor is dead when on the track and the e-unit is trying to function all it does is buzz. Having said all of that now I have another question, if the collector wire is bad what is powering the e-unit when it is sitting in the frame and on the track with power coming from the transformer?

[steve1946]

Got the #736 running well this morning.  Someone soldered the motor armature wire to the wrong place and after studying the wiring diagram I resoldered it to the center lug on the brush plate along with the green wire (bottom wire) from the two-fingered plate coming from the e-unit.  Thanks for all of your comments.

 

Steve