First Tow Home - Engine just died.

[freeflyernc]

So I have had a 2005 Launch 21v that we have put 900+ hours on and this weekend was the first time we were stranded on the lake. The boat started losing power (like someone pulled the emergency cut-off lanyard or turned the key off) at any speed. It was very random and we were on glassy smooth water. A little while later it did the same thing, but instead of a momentary loss of power it just shut down completely and wouldn't re-start.
I did some diagnostic work and found that there was no power to the fuel pump. I checked fuses (in the front and rear) and then I by-passed the neutral safety switch and oil pressure switch, again with no luck. The boat will turn over, but nothing else. I was thinking of going to buy a new lanyard safety switch as my next test since I can't jump it like I did with the others. Anyone have any other ideas? The boat was running perfectly until this happened.

[lively]

Do you have wiring diagram of where the fuel pump gets it's power input ?
What have you verified ?

Fuel ?
Spark ?
Compression ?

Sent from my iPhone using Tapatalk

[SquamInboards]

You verified that the pump has no power, did you try supplying it with power momentarily? Then you'd know if the pump was fried, or if there was a power supply issue. Also, before getting a whole new lanyard switch, take the old one out and physically connect the wires that go to it. That would tell you if it's the lanyard switch itself.

[freeflyernc]

I checked the lanyard switch and that is not the issue. I also just replaced the 3 relays near the computer- I know one is the fuel pump, one is the starter, and I don't know what the third is. This also made no difference. I have not tried to power the pump alone yet- that is my next step, but I don't get any power at the pump with the ignition on. I also found the quick connect for the pump and checked there for power, but I get nothing. The mechanic at the Supra dealer seemed to think it was a relay issue, but I have eliminated that. Any other thoughts before I tow this turd up to the dealer?

[lively]

So you have checked power from the output of the relay and you have power ? If you do then it's downstream to the pump . Do you have a wiring diagram ? If so post a pic


Sent from my iPhone using Tapatalk

[freeflyernc]

I don't have a diagram- I haven't been able to find one.

[freeflyernc]

Indmar was nice enough to send me a diagram. It is attached.mefi.jpg

[lively]

I can't read it . Send to [email protected]


Sent from my iPhone using Tapatalk

[lively]

Verify power from pin 30 to relay and then if power is there . Verify power to pin 87 with ign on . Then report back


Sent from my iPhone using Tapatalk

[CJD]

Just to make sure...the pump power will only last for a couple seconds if the engine is not turning. So, if you are turning on the key, then moving to the engine to check the power, the power will already be off. It will take your first mate turning the key while you test the power at the pump to check it.