ALCO RS3 Control Panel

The Oklahoma Railway Museum has two RS3 locomotives with the 244 prime mover. We believe these were on the Magma RR; they are missing their builders plates.
One of the units is setup for MU operation. This is the loco we are restoring.
A mouse has assisted us with the wiring in the control cabinet.
We have managed to trace and repair some of the wires but are scratching our heads on the rest.
The parts catalog references a Type 17FR28A1 Panel which is a 1500 ohm fixed resistor and a 5 ohm tapped resistor; the tapped resistor is the shunt for the load meter set to 4.4 ohms.
What is the 1500 ohm resistor for?

Thank You
Terry

Are these the two that were formerly on the Blacklands Railroad? Former Magma #2 and #3.

Yes, we believe that these are from the Magma railroad, one loco is still in the Magma livery.
Is the builders plate the only location the serial number was shown?

I have a couple of Terry Kirkland photos of #2 and #3 at Sulphur Springs, TEXAS dating from 2000. Neither one has a builder's plate showing. I don't know if ALCO stamped the frames, but am sure someone on this list will know.

I found a roster note from the old Sy Reich Railroad Magazine roster book. San Manuel #2 became Magma #2. SMA #2 was ALCO Serial #81289 built in 3/55. It is entirely likely that SMA #3 became Magma #3. SMA #3 is ALCO Serial#81288 and was also built in 3/55. Serial numbers from R. Craig Rutherford's Diesel Shop website.

We have a wiring schematic that was purchased showing the RS3 with MU, the drawing is 10 to 12 feet long.
I found the resistor in the parts section of the drawing, it is labeled 'Discharge Resistor'; the reference to a location on the schematic is blank, I've been searching the schematic with no luck so far.

Terry

Hi, The Resistor 1500 is in the GS1 Magnet.
43B-4 43B is the top in and the 4 the bottom. The prevent GS1 and GS2 from flash the magnet.
Look at the drawing.
Look at Section K and AB.
This is take from MM-8839428 with the a John Mech [email protected] yes on no sent to you if 501C.


Thank you

Stan

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