I have had this issue before where the ecu fuse would blow if the battery isnt grounded 100% Its happening again. And I dont know how to fix it. I had done a battery relocation yesterday and no matter what I do the ECU fuse pops instantly when I power it up. I have a multimeter but I dont know what to test. Im running out of fuses.

Everything else works when I power up the car except the ECU fuse pops instantly. Really need the car running since its my daily.

Edit: is the CAS a live wire that could be grounding? That's the only wire that's suspect.

 

CAS is passive ( reluctor signal )

are you blowing the FC/FD EGI fuse,, or blowing the main fuse in the haltech fuse block ?

 

Since the Sprint doesn't come with a fuse box, it's really hard to have any idea at all what you're talking about. You need to be much more specific.

 

I fixed it. It was the CAS wiring which kinda fell apart where the old plug connects to the Haltech harness.