I have an 83 e25 camper with a 7.5. When trying to crank for first time in years small fire started on the top of engine. It will still crank and run but when cleaning up the mess found on wire harness damaged that appeared to for the choke and had 2 other connections further down but can not tell where they go. There is also a small threaded opening and I am not sure what goes there. The camper was given to me and I am not sure about the history. The attached photos are the best I could get. The orange screwdriver is in the threaded hole.

 

I'll bet one of the wires is the oil pressure sending unit (for the dash gauge/idiot light).






No idea what the hole is, I can't see anything.

 

The oil pressure connection was not damaged I had disconnected it to get it to crank. Once cranked I would plug it back on. The connectors appear to be in series off of the choke. As for the hole I placed the screwdriver in it to keep trash out it is threaded but I did not see anything in the area that would go there. I am just at a loss.

 

If you can get it running again, see if there is suction on the hole the screwdriver is in. If it sucks a lot of air(it may stall if you pull the screwdriver out) then that port goes to manifold vacuum.

I can see the fire melting the plastic top off a manifold vacuum tree or some other gizmo, but there still should have been a metal part screwed in the hole that would not have melted.

 

Isn't that an open port seen to the left of the EGR valve and above the oil pressure sender?

 

Temp sender unit goes there?

 

I'm really wondering what's up with this...

That connection should bring the gauge to ground.
The only connection to 'run' is through the ICVR.