new board installation

Thanks for the reference ...I will have a look....

Okay , I looked over the above reference on  the board installation and best I can figure out all three wires coming off the board are group together and wired to male plug. That means only one plug goes from the tender to the engine. Not sure I got that right and it doesn't seem right to me. Any help would be appreciated...Thanks

Thanks Mr Barry on your observation about the engine and tender. I would still like to connect the new board that I purchased .  I reviewed the drawing that you advised me of but I am still confused as to what wires go to male or female plugs. The best I can figured all three wires connect to the male plugs???? Not sure this is  right...Any help would be appreciated....Thanks

Barry I am Attaching photos of what I working With. Thanks for any help.

I don't own any Mighty SOS engines, but I can give you some general guidance.  The 3 wires top to bottom are LIKELY center roller, ground (outside rail), and chuff switch.  This is based on the trace sizes and that the ground connections often run around the periphery of a board.  YOU NEED TO VERIFY THIS WITH SOMEONE ELSE.

The second problem is where to connect them.  There should be another tether coming through or under the cab. In other SOS engines, a polarized 3 part tether was used.  You will need either pull off the boiler or continuity meter the 3 wires.  One should connect to center roller, another to ground, and the third should connect to ground intermittently depending on the position of the drive wheels.

There should be 2 additional wires (not shown) that connect to the speaker.

You may want to post a picture of the locomotive tether.  Hopefully someone who has this engine will be willing to pull the boiler and tender shell and give you correct information.

Bob

Thanks RRDOC .... in an earlier post on this subject ,their was a diagram on how to connect a three wire situation to a two wire hook up. Unfortunately, I was unable to figure out where the the wires had to be connected. If someone could guide on this it would greatly appreciated. Thanks for all your help so far.....

As a follow up to your review , to the left of the board is the 2 wires ( male and female plugs) that coming of the engine. Hence, my dilemma, 3 wires  coming off the board to the male/female plugs . Not sure how to hook up the three wire  to two plugs.

I see NO posts from Vernon in this thread.

@PRRMP54 posted:

I see NO posts from Vernon in this thread.

I believe it was a different thread for the same issue.

Okay, I will add my 2 cents and maybe it will help. You are replacing the original sound of steam board, ( 8002-T20) which is analog, to a digital board (8215-T15). That is why all the IC's on the new board, They don't operate the same. You will need to do some minor rewiring to the locomotive. The chuff switch on the locomotive smoke unit will not be used. You will still need a power wire from the locos E unit terminal board and a ground wire to the locomotive's brushplate screw. The third wire is what is used to send a chuff signal by measuring the field voltage to the new board. The third wire is connected to the field winding on top of the motor brushplate. So you will now have 3 wires from the locomotive. Enclosed are two diagrams. The first is the wiring between the locomotive and tender. The second is if you wish to change the chuff rate. You will need to enlarge them to read. Hope this will help.