Last week my 4Runner (2004 V8 limited) died, and wouldn't restart. With key on, there was no CEL like the ECU wasn't getting any power. All fuses checked out to be fine, checked by swapped a few fuses around and everything was still working with the swapped fuses. Checked with a volt meter and was getting proper voltage at the fuse and the ECU itself.
I figured the ECU was fried and a local salvage yard had one, so I went to pick it up and try it out. Still no CEL when the key is on before starting it. Swap the ECU back, and the CEL is on. It was able to start for a bit, but then I turned it off, and a couple hours later tried it again, and there was no CEL again. I'm assuming it's either the dash harness or the engine harness that has a short or corrosion, but I'm not sure what to check. Anyone have any ideas what to test before I start buying harnesses?
Vehicle history: 2004 V8 Limited. 230k miles. Hasn't seen a water crossing in three years. I haven't had any problems with it in a long time, this was the only real break its had since 2019 when the alternator went out.
I figured the ECU was fried and a local salvage yard had one, so I went to pick it up and try it out. Still no CEL when the key is on before starting it. Swap the ECU back, and the CEL is on. It was able to start for a bit, but then I turned it off, and a couple hours later tried it again, and there was no CEL again. I'm assuming it's either the dash harness or the engine harness that has a short or corrosion, but I'm not sure what to check. Anyone have any ideas what to test before I start buying harnesses?
Vehicle history: 2004 V8 Limited. 230k miles. Hasn't seen a water crossing in three years. I haven't had any problems with it in a long time, this was the only real break its had since 2019 when the alternator went out.
