1987 V10 5.7TBI p/s belt question

[Gander]

So here’s the question. My truck has all the options, p/s, a/c, etc. it’s also had the AIR pump deleted so no belt for it. When I got it, it had 2 belts off the p/s pump. The inside belt just on the p/s pulley and the crank, the outside belt off the p/s pump to the a/c compressor and then I think a groove on the water pump pulley maybe and then back. I’m not sure.

Yesterday I noticed something a little funny with the power steering. Not much but just a little bit. Seemed like in between the shift from reverse to drive backing out of my driveway I wouldn’t have power steering for a second. Opened the hood today and found a broken belt jammed behind the pulley.

So here’s my question. There are 2 grooves on my p/s pulley. The inner groove lines up with the crank pulley and maybe ran to the AIR pump on the other side originally but was just running from the inside groove of the p/s pump to a groove on the crank, I don’t know, can’t find a belt diagram. The front pulley runs from a/c to water pump to crank and then back to p/s. Do I even need to replace this broken belt on the inside groove of the p/s pump if my outside p/s belt looks good? Is there an advantage to having that second belt on there? Am I overthinking this?

 

[Gander]

Update, I went ahead and replaced all the belts, including that one that broke.

 

[Gander]

So an update on this. Found the cause of the belt coming off. Bracket bolts for P/S and A/C were loose. Looking for what may have caused that and found both motor mounts shot and trans mount shot so my guess is the excess vibration shook some bolts loose? Replaced all, tightened everything up, and all’s well that ends well.