Ok long time reader first time poster. I own a 1998 chevy blazer lt 4x4 4.3 w vin I am have some electrical issues. Almost every time I start my truck I have to touch/jiggle the thick wire harness left of the motor and right of the battery ( I will try to insert a picture). But when I turn the key to on I get no day time running lights no crank or click. Once I touch the wire mentioned earlier the day time running lights come on and I know the truck will start. Also when this happens my PRND321 and my mileage don't light up. Also when I am driving every light on my cluster will light up and shut off this happens every now and again. Ive searched and googled for answers couldnt find a thing. Hope some has answers as I am sick of jiggling the wire in order to start my truck also every time.

 

hate to state the obvious but there is a broken or shorted wire in the harness you mentioned. you did the hard part by finding the harness with the problem bc this is often the most time consuming part of the repair. so now CAREFULLY cut the tape holding the harness of wires together and separate the wires (per Se) this will allow you to visually check for any obvious defects in the wire. if nothing jumps out at you then you should shake pull or handle the wires in small groups until the single wire causing the problem is found. also check to make sure batt terminals are tight. KISS keep it simple silly. hope this helps please let me know. i love electrical problems......on others' cars of course.

 

check the grounds

check the wires (open the plastic)

replace wires if needed make sure you check every thing

 

Any certain color wires that I should look for also about the grounds where are they located and if I do find a short or broken wire what is the best way for repair and any other tips tricks or diagrams I should know

 

I had an ongoing issue similiar to what your describing. I disconnected the plug and found that several of the female connectors had bent open. I took the wires out of the plug with a scribe and the bent the tabs back into place. So far so good. I have been tracin electrical issues for some time and dumb luck led me to this issue. Good Luck.