You’re correct, it the unit at the bottom left of the picture, under and slightly to three left of the water pump. If memory serves, it’s one bolt that needs loosening off a bit - the one a little bit up from the bottom left of the pic. Once slightly loose, get a long lever in between the pump and the block (e.g. long screwdriver or breaker bar) and yank on that to the left to tighten the belt, then tighten the bolt. I do wonder about the condition of the belt though to get that loose, so make sure it’s ok. Sent from my iPhone using Tapatalk