What are the differences between the *meaning* of a 'warranty' and a 'guarantee'? I tried looking this up online but received conflicting, confusing results.
I don't really think that there is a difference in meaning between the nouns, for most speakers of BrE. However, there may be for some. Here's one opinion: Difference Between Guarantee and Warranty | Difference Between | Guarantee vs Warranty
I agree that there isn't all that much difference between the two. If I had to make a distinction, it would be that a guarantee is a promise that nothing bad will happen, while a warranty is a promise to fix something if it does go wrong.
You get a money-back guarantee if you are not completely satisfied with a product, but you get a 5 year warranty on your new car's drivetrain.