1981 3406A gauge and light sender question.

I am cleaning up an ‘81 W900A with a 400 A model cat. There is a 2 prong sender on the RH side of the block that has no wires going to it. No wires missing or cut on firewall for it. What is it for? If not needed I’m gonna remove and plug hole cause it looks crappy not used. Also this engine seems to have 2 coolant temp senders. One in usual spot next to stat housing and one in the middle of head behind turbo. They both have been spliced numerous times and run together into cab and are sketchy looking. Electric gauge works with key but does not read so i am going to troubleshoot that sender by the stat. Most likely run a new wire for it or both. Is the middle one for idiot light? It does work.

 

@Inderjit. It has mechanical oil pressure gauge plumbed in on Lh side rear. It has two senders on Rh side for oil. One next to oil supply for turbo and the other one towards front on oil cooler. I assume those are warning lights for oil temp and psi. It has oil temp gauge sender in bottom of pan like usual. That all works. @wore out that makes sense. It just looks odd. At first I thought maybe it had one of those old Kysor shutdown boxes in the dash somewhere and that was an old sensor for it. This truck doesn’t have that. I’ve seen that crap on a handful of old Cummins powered trucks. This is really the first Cat powered truck I have spent this much time with. This truck is solid and runs great. Not much has been screwed with.