@cbbr It's always helpful to know what model and what year.
The repair manual (FSM) and the electrical wiring diagrams (EWD) are in the Resources section for free download.
The online electronic parts catalogs (EPC), such as
PartSouq, have all the parts listed for each model and year. You can look them up using your VIN. It's worth getting to know how to use the catalogs. They are very useful for understanding how the truck works, as well as repair insight and, of course, part numbers. Don't be discouraged if the part number you're looking for is listed as not available. Not all online sellers have all parts.
US domestic online sellers, such as
Ourisman in Richmond, Virginia and
Lexus Parts, sell Toyota/Lexus parts directly at significant discounts. You'll also need your VIN for these sites, but their catalogs aren't as easy to use. They will, however, list all the parts you can get from your local dealership, with few exceptions, whereas the overseas websites sometimes do not.
If the parts are stocked in the Toyota regional warehouses, your dealership can get them next day. The online sellers, while being less expensive, take a few days to weeks to get your order to you.