Bsalinaz

Not the alternator I’ve checked the alternator and wiring from starter to the fuse box and I’m not dropping voltage on any of these including the battery, it only happens to the ecu under load so I’ve contacted wiring specialties to see where the ecu is getting power cause I’m getting a voltage drop on that wire which I just found today but none of my connectors are labeled power. I did run a separate wire to double check and sure enough I was stable at about 13.5v even under load

I think we’re having the same issue as I drive my battery voltage is dropping at the ecu but my battery is still charging around 13.8v? Let me know if you figure out your issue I’ll be digging into mine this weekend as well! Also I wouldn’t say 13.4v is low for charging to me it doesn’t sound like an alternator issue.

So I have an s13 with a 1jzgte I’m having an issue with my voltage reading 12.5-13v at idle at the ecu but as soon as I drive the higher my rpm the more my voltage drops about down to 11.5v. I checked at my battery and I’m reading about 14v at idle. Also noticed when it’s cooler outside my voltage doesn’t drop as much? I have grounds from the harness to the block and from the block to the chassis also the battery is in the trunk and ground is to the chassis I’m confused on what’s drawing power while driving could this be due to a bigger fuel pump?