This installation documentation is for the HO-Scale Intermountain GE U-18B "Baby U-Boat." This installation uses the T1P-MH decoder, and was performed by Walter Fonda, of New York State.
The three pictures above show the Intermountain GE U-18B baby U-Boat prior to the decoder Installation.
Using a #17 blade, gently lift the long and short handrails from each side of the loco being careful not to cut off the mounting pins. Set the handrails aside for later reinstallation.
Using a very small screwdriver gently release the body mounting tabs from the chassis. The tabs can be seen under the trucks. Inserting a small piece of cardstock between the tabs and chassis will keep the tabs from relocking. Starting at the rear and working towards the front, wiggle the body slightly from side to side while lifting until all the tabs release. With the tabs fully released grasp the body shell and pull straight up and off of the chassis.
Remove and discard the DC plug from it's socket. Plug in the decoder so that the Orange wire lines up with Pin #1 of the socket. Pin #1 will be designated with a "1" or a small arrow/chevron.
Place the T1 Decoder face down in the black tray over the rear flywheel and dress the red and yellow wires over top of it. Fold the decoder wires over top of the main board to keep them out of the mechanism. Reassemble the body shell on the chassis keeping the body parallel with the chassis. With the chassis on a firm surface, gently press the body back down onto the chassis until the tabs lock. Finally, reinstall the handrails and other details.
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. It will damage it. Use only Rosin core solder approved for electronics use.
We recommend to use only Kester "44" rosin core, SN63PB37, .015" diameter, part number 24-6337-0007.
This can be ordered from Techni-Tool under Techni-Tool part number 488SO157
Other solder tips
When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire