mercusier alpha 4.3L TKS (Turn Key Start) Thunderbolt V electronic ignition issue

[blakes52]

i had an issue with the termperature sensor a week or so back where the wires that lead from the sensor were melted, causing the 20amp fuse and 50amp circuit to pop. this killed my ignition system (no power at all). long story short i replaced the temperature sensor today and went for a quick test. after resetting all of the popped fuses and circuits power returned and the motor started and functioned normal. thinking all was good i went to shut off the boat and neither the key or the kill switch would turn the engine off. finally i popped the circuit manually and it shut off. when power is returned to the circuit the fuel pump (i believe) is constantly running. does the pump need to be replaced or is there a relay or something that controlls it. thanks

 

[Bondo]

i went to shut off the boat and neither the key or the kill switch would turn the engine off.

Ayuh,..... Welcome Aboard,..... It sounds like maybe some more wires were burnt, 'n shorted together, or you wired it back together wrong,.....

 

[Bt Doctur]

the temp sensor or switch operates on a ground condition , really no way for the wires to melt you sure it wasnt an alt issue?

 

[blakes52]

i found this diagram and noticed it said something about a diode so i checked that this morning and sure enough it was shorted.