Electrical Gremlins

[txmxer]

Hey everyone, boat is a 2007 22i with 5.7 marine power. It has been sitting while I rebuild it, fired up before the rebuild.

Now the boat has power to the dash but no fuel pump prime and no communication to the motor or ecu.

I’ve checked all wiring, neutral safety switch, fuses, relays, cleaned up the ground to the engine block, and lastly, I sent the ECU out and it tested fine.

Myself and my shop are at a loss. Any ideas from anyone?

[txmxer]

Bump

[boatwakes]

Track down where it loses power starting with the purple wire at the back of the key switch. The purple wire is supposed to get power when the key is in the "on" position and then sends power back to the engine. There are fuses for the ECM, fuel pump and ignition on the engine so next test there. If you have power to everything and no other reason for loss of power on the engine, your ECM may have fried. Post a photo of the top of the engine with no cover on it please.

[txmxer]

Thanks will do! I did originally trace the purple wire from what I can remember but I’m going to start from scratch.

I had the ecm tested by a company that repairs them and he confirmed nothing wrong with the ecm.

[txmxer]

Have power going into the ecu, but no power going out. Confirmed the ecu is for sure good.

We’re scratching our heads

[boatwakes]

Where are you testing for power out of the ECU?

[txmxer]

I'll have to ask my mechanic, he told me that information yesterday. Electrical is my weak point so I'm having the shop go through everything to double check.

I didnt have these problems before a sketchy shop install guy put a new stereo in, I dont know if its been a coincidence or not.

[txmxer]

So were still stumped, power is confirmed going to the ecu but no power out of the ecu to power the starter. It is a brand new marine power starter. Would the crank position sensor have an effect on this?

Weve basically isolated the problem down to the ecu, but the ecu has tested fine.

[boatwakes]

So where are you with fuel pump prime? The neutral safety switch is responsible for sending the start signal to the starter from the key switch but it's not clear where the original problems are right now.

[txmxer]

No fuel pump prime or alarm beeping at all. I had originally checked the neutral safety switch when I was going through the wiring the first time. Thats really the only thing left I can think of, it really is giving all the symptoms of a bad ECU which is confusing. A bad neutral safety switch could give the symptoms were getting though so I think you may be onto something. Going to give my regular mechanic another week and then I'll probably take it to a tige dealership, really dont want to get to that point.

[boatwakes]

Who did the ECU testing? It really sounds like it's bad and I do know there's a couple "guys who test them" who don't know what they're doing. Also, what year and engine configuration?

[txmxer]

Who did the ECU testing? It really sounds like it's bad and I do know there's a couple "guys who test them" who don't know what they're doing. Also, what year and engine configuration?

I went through OBD diagnostics (OBD2allinone.com) who I heard about on here, any experience with them? The boat is a 2007 Tige 22i with 5.7 marine power. It really does seem like a bad ECU, I was sure thats what it is and my mechanic thought so too.

[txmxer]

No luck on the sensors. Marine engine depot (the parts supplier for marine power) said to check the red wire coming directly from the battery to the ecu that powers the ecu. We will double check that wire next. Otherwise it has to be a bad ecu

[txmxer]

Really getting close to the point where Im going to pull the trigger on a new ecu, but it just does not make sense if it was able to run a different motor when they tested it.

[boatwakes]

They don't test them on engines at that place, they look for wave form output from the ECU which is why it's not a good test.