Q: Replacing alternator on my 2000 Rav4. Is there a bolt under alternator on bottom left?

The adjusting bracket has one bolt, Toyota Part number 91621-60845. The adjusting bolt that you broke is part number 90119-08299. This bolt should not bottom out so you should check for the possibility that the belt is the wrong size or worn. For a used used belt, the tension should be set to 100 pounds and you must use a gauge, otherwise there is no way to tell what the tension is. As far as the bracket that holds the alternator, that bracket is bolted to the engine with three bolts, all part number 91651-G1028. All kinds of articulated and remote access specialty tools are used to access bolts and parts. I can guarantee the bolt that you are referring to is accessible but I would have to see it to specify exactly which tool to use. More likely than not you will have to buy an adapter. Even after 30 years, I am still buying them and sometimes have to make them on the lathe. A certified mechanic will have all the required tools and can finish this up for you if you desire. Simply use YourMechanic’s alternator installation page; obviously you will only be charged for the time required to resolve the bolt issue, adjust the belt (or install a new one) and test charging output. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.