l5 auto wiring or engine problem?

[yakusza]

my Symptoms:

1.electronic device going crazy(RPM meter,temp meter,radio player,headlight) when gear is at Reverse.
2.when cruising,Symptoms 1 happen if acc pedal realease but all went normal if acc pedal is step on.
3.i perform DIM(do it myself) check,i touch a metal to car engine,there will be a spark..WTH..??

now my engine wont start at all..

any pointer,suggestion,diagnosis muchly appreciated.

 

[xtremeleo]

wth indeed sir, sounds like wiring problem. what had been done prior to dis problems?

 

[yakusza]

the last electronic device i installed was Power amp..but it was 1 year ago..

if it wiring prob,care to share where should i check first..?