2000 alpha v8 no power on purple wire cranking

[scoflaw]

Not my boat. 12volts key on. 0 cranking. Fires up hot wiring purple. Any likely culprits?

 

[alldodge]

More info please. What 2000 V8, carb, EFI other?

 

[Bondo]

Not my boat. 12volts key on. 0 cranking. Fires up hot wiring purple. Any likely culprits?

Ayuh,..... Look to the outside tiny terminal on the starter's solenoid,.....

That terminal feeds battery voltage to the ignition, Only while crankin' on the starter,.....

 

[scoflaw]

Efi

 

[scoflaw]

Ayuh,..... Look to the outside tiny terminal on the starter's solenoid,.....

That terminal feeds battery voltage to the ignition, Only while crankin' on the starter,.....

Thanks, will advise owner. Your talkin solenoid on the starter, right. Some manuals refer to the slave as a starter solenoid.

 

[alldodge]

Efi

Like pulling teeth I guess

You said 12V on the purple wire goes to zero when the starter is engaged. The EFI does not transfer power from the starter to the fuel pump while the starter is engaged. In any case power is removed from the purple wire.

Where is the 12V going to zero being measured?

 

[achris]

Sounds like a faulty key switch... If 12v is on the purple when key ON, but drops to zero when key moved to START, that can only be the key switch...

 

[scoflaw]

he has no spark when cranking and the gauges die, not sure where he is measuring from. Has power to the r/p at the key switch.. He has tried 3 different key switches. Don't have his engine number, the motor has the electric carb with 2 throttle bodies on top. Was thinking shift interrupt or neutral safety but don't have a wiring diagram for his engine.

 

[achris]

... the motor has the electric carb with 2 throttle bodies on top. ....

???? WHAT ???? :facepalm:

Neutral safety stops the engine cranking. So it's not that.
Shift interrupt just stops the spark being produced, doesn't mess with the voltage on the purple or the gauges.

 

[achris]

... but don't have a wiring diagram for his engine.

If you want a diagram, we'd need to know which ECU he has, MEFI1 or MEFI3....

 

[scoflaw]

I just sent him a note about what kind of switches he's been using. Doesn't make sense that he loses power to purple cranking. Thanks for the thoughts

 

[alldodge]

I'm going to assume power on the purple is not being lost at the key.

On a EFI motor Purple changes to Pink when it connects to the EFI harness. Pink energizes the MPR which transfers power to all other circuits including coil.

I'm thinking corrosion in the EFI harness connector or MPR or main power connector

 

[scoflaw]

I just told him to check continuity at the switch between Batt. and ign. when the key is in the start position. Sure sounds like a switch problem to me. He's got power to the r/p at the switch and power leaves the switch on the purple wire and next in line are the gauges. So his gauges die in the crank position, so not sure how corrosion down the line would effect power to the gauges.

 

[alldodge]

I just told him to check continuity at the switch between Batt. and ign. when the key is in the start position. Sure sounds like a switch problem to me. He's got power to the r/p at the switch and power leaves the switch on the purple wire and next in line are the gauges. So his gauges die in the crank position, so not sure how corrosion down the line would effect power to the gauges.

Always good to have more info when asking a question to others. Good luck

 

[scoflaw]

Resolved.... Jackass had the ign. switch wired wrong. just can't fix stupid. Thanks for listening

 

[Scott06]

Resolved.... Jackass had the ign. switch wired wrong. just can't fix stupid. Thanks for listening

So he failed to mention I just replaced the switch or rewired the switch ?

 

[scoflaw]

All he had to say was "worked fine 1 day and not the next" Go figure