Tom S with the new to you 149 TOMCAT - I see Ken F provided you some good info, but I also know you're really just finding your way around this site. If you go back to the opening page for the entire Forum and scroll down the list of Topics you will find one titled "Manuals" and one titled "Wiring Diagrams" (almost at the bottom of the list). To find the Operator Manuals and Service Manuals for your 149 you need to select the Manuals thread, then select either of these, then select "1x8-9" to get to the manual for your 149.
To help you understand, your Model 149 is part of what we call the "1x8-9 Series". This includes the Models 108, 109, 128, 129, 149, 169 and 86. Model numbers in this series that end with 8 and 6 are gear drive tractors. Model numbers in this series that end with 9 are hydrostatic. All these models are covered in the same operator and service manuals.
When you go to the Wiring Diagrams thread it will give you 2 choices. The top one is a really large pdf file covering almost every Cub Cadet ever built, by IH or by Cub Cadet Corp. The other one you can select is Roland's Fancy Colored Wiring Diagrams. When you open this you'll see a list to scroll thru that provides a schematic for each of the IH Cub Cadet models. You may have to open this a few times in order to get all of the models to open. When I open it most of the time I just get a little square box with a X in it for many of the models, so I try and try to open it until I get the model to show that I need. Today I can't get the 1x8-9 diagram to open but I think you'll also find it in the Service Manual itself.
If you're like me my computer is a long distance from my tractor, and I still like having a paper copy close by, so I'd still recommend getting one from one of the sponsors.
Hope this kinda helps.