Car has been in limp mode for a while. Had a error code for top dead centre sensor got a new distributer, fixed it, now im getting code 4(crankshaft sensor) which is inside the distributor. I did research and people said check the wiring to the ecu. In the pic below is it connecting to the ecu? Cause it looks a little burnt.
if so how would I test it using a multimeter

 

what year? and what engine? only then will we be able to help you, but i do have resources to share like this, also i highly reccomend picking up a voltimeter to see if you are actually getting current to the plug, or if its your wires/plugs

 

91 accord lx
2.2L
I have a multimeter do I test it by putting the ends in the plug, wheres the negative and postive side in the plug

 

should be similar to what GhostAccord said here