No Power to ECU RB25

[OBTRICE]

I plugged up my RB25 in my S14 (95) last night, but could not get power to the ECU.

I purchased the swap out of a running S14 so the harness was already completed. I pulled my SR out and dropped the RB in. Im using the 240 lower harness.

There is a plug on the top of the engine that is the exact shape and fit as the TPS that is not plugged in, but I cannot see that stopping ECU power. Plugs in the kick panel and grounds are all fit and set. Im pretty stumped.

Any help would be massive. Thanks.

[240z4u]

Are the power relays present on the harness that you installed? The main power runs through the "eccs" relay. Sounds like its time for you to take a peek at a wiring diagram to familiarize yourself with everything.

[OBTRICE]

The power relay is the blue plug that connects in the kick pannel correct? I have that there. Three plugs that came through the firewall, Big blue to the ECU, the white long one that plugs in the slot on the kick panel and a blue squarish relay looking plug that plugs into the kick panel.

I've been looking at every diagram I can find but still no clarity for me.

A picture of my harness if that helps the situation any.

[s13_240_rb20]

I was playing around with my rb20 wiring yesterday, and I know of 3 wires that are mostly needed. I had two run to the battery (for ecu power and ecu memory, I think) and then I had one ran to the fuse box to get a key on/off "switched" power. This is the IGN wire on a schematic. Without the IGN signal (that the key is on, the ecu will never turn on).

--TJ

[Darius]

Ok so you're saying the long white plug (M63) plugs into the stock S14 dash harness, right? That's needed.

The long blue plug goes to the back of the ECU, obviously. But I only see one on your wiring harness unless it is tucked underneath near the ECU plug.

There should be two blue relays (squarish thingies with a wiring diagram stamped on the top of their covers). Those need to be in place or either the ECU will not get power or the ignition system will not get power.

I'm not sure what you mean by plugging into the kick panel??

[240z4u]

Darius, the stock relay bracket is located in the kick panel. I notice a missing relay as well.

Evan

[michaelwinne]

Alright guys sorry to bring up a 3 year old thread but I'm having a starting issue and I see Darius around on here all the time and it seems like you have a lot of knowledge pertaining to RB's. I'm looking for the ECCS/ignition relays that are supposed to be on the wiring harness and I'm lost. I have a Chase Bays wiring harness if that makes any difference. Any help would be greatly appreciated!

[95_240]

A new thread would have been better because it's not going to be related to the issues this guy was having. I can tell you right now that ChaseBays harnesses suck and that thing is going to be a huge problem. Send it back and go with a different company.

[RRRRB]

seems like everyone has had a problem one time or another with ANY of the wiring harness services... but before blaming the company.. make sure everything on your end is good

[USMCgetsome]

do you know how to use a multimeter? if yes then use the wiring diagram for the rb25det to check the power signals to the blue plug.