Fuel Pump not energizing

[jeffreyk573]

I'll try to keep this from getting too long. But, this last Sunday afternoon on my way back to the boat dock at the end of an entire day on the water, my boat sputtered, and died. This same thing happened last summer, but after about 20 minutes, I was able to get it started, and returned to dock. I thought at the time it was the fuel pump. I replaced it, but that wasn't it. Replaced the two fuel pump relays, boat started right up. No issues for the rest of the summer.. Then this last Sunday, she died. Would not restart at all, and had to be towed back in. By a pontoon boat of all things, but God bless them. I can tell that the fuel pump is not energizing. It's pretty loud. I have replaced the relays, again, but it's still not energizing. The two main things these two occurrences have in common was EXTREMELY rough conditions. I mean slamming the boat. And both times I had used my 12volt inflator. I'm not sure if that could have anything to do with it or not.
But if anyone on here has any ideas, I would like to hear them.

[jzelt]

Have you tried 12V directly to the pump terminals and see if it runs?

I had similar issue a few years ago. My pump ran, then just died. Put 12v on the pump and it didn't work. Replaced pump, but still no power to it. 12V straight cycled the pump. So I took it to a mechanic, who had to remove the bottom panel behind the bench seat, and there is a ~20amp fuse by the V-drive. I like you replaced the relay prior to taking it to them.
I don't have a pic or still any working knowledge of the exact location, just that I know that is where I will look next time first.

I PM'd with another user recently about them having the same issue, and he later replied that after talking with Indmar and Supra a few times, one of the finally mentioned the same in-line fuse.

[CJD]

That brings up a question...for trouble shooting items like this, is there any way to get a Supra wiring diagram?

[jeffreyk573]

Thanks for the input. I did actually find a fuse holder that had three fuses. I believe that one fuse was fuel pump, one was ECM, and I'm not sure what the other one was. I pulled all three, and checked them with a meter. They were good. But that doesn't mean there isn't another one. And a wiring diagram would be quite handy. I did check my kill switch. It seems to be working correctly. I live two hours from where I have the boat, makes it a little hard to keep trying different things as they pop into my head. I just don't think it's anything big. But I have to find it.

[jeffreyk573]

I wanted to put an update to my original post. After spending hours troubleshooting, and replacing every relay, again. I finally found the reason my fuel pump would not energize. There is a quick connect pigtail that comes off the fuel pump. It was hidden up behind the K&N air filter. This is a little over a 12inch wire run, with the connection in the middle, kind of just hanging there. In really rough water conditions, I guess it was able to move enough to lose connection. Cleaned it, tightened it, and SECURED it. I haven't been able to spend the day on the water with it yet, but I'm sure this solves this issue. Jzelt, thanks for your input, I was looking for that fuse you mentioned when I found the loose connection. Hope this helps somebody else out.