Would like your feedback. I installed a Carter P4594 electric fuel pump, Low Pressure Oil Switch and a relay to run the pump about a month ago. Last week the pump failed. No warning signs, just quit. I applied 12 volts directly to the pump but it is dead. I don't know if it just failed or burned up. I confirmed the Low oil pressure switch is working and I confirmed the relay is closing. I put my Fluke meter in series with the fuel pump wiring and only measured 10.75 Volts. I know I should have 12 volts going to it from the relay I installed. I'll need to double check that measurement to insure I was properly connected. If I measure same voltage then not sure where I go from there. I spoke to Carter tech support and he confirmed that low voltage could cause a premature pump failure. Looking for any guidance in how to identify where the voltage drop may be coming from. I removed my battery and plan to have it checked. I confirmed that my alternator is supplying 14.03 volts with motor running and all accessories on with full load.
Not sure if the following would have had anything to do with it however, I had a slave relay for the start circuit which I cracked when terminating battery cable earlier in summer. I epoxied it, and it cranked the motor, I intended to replace but I forgot to replace it once the summer got started. The motor has been slow to crank when its hot, and I suspect that slave relay was the culprit. I have the control leg (Terminal 86) of the fuel relay connected to the ignition terminal of the Slave Relay because I could not think of any other ignition source to connect and didn't wan to run a separate wire all the way to the helm. My ket switch already has two ignition wires terminated on the "I" screw. I cant see how the slave relay may have affected the ignition terminal but perhaps it did. I've ordered a new fuel pump, slave relay and another fuel pump relay just in case.
I plan to double check the voltage of the fuel pump relay to confirm if its not getting sufficient voltage. If it is not getting at least 11.5 V then I need some guidance.
Relay wiring
86 - to Slave Relay "I" Terminal (16 AWG)
85 - To Battery Negative (16AWG)
87- To Fuel Pump Positive (12 AWG)
30 - Battery Positive - (12 AWG)
Fuel Pump Negative to Engine Block (ground)
What am I missing? Is is appropriate to terminate terminal 86 of the fuel relay to the "I" terminal of the slave relay?
Not sure if the following would have had anything to do with it however, I had a slave relay for the start circuit which I cracked when terminating battery cable earlier in summer. I epoxied it, and it cranked the motor, I intended to replace but I forgot to replace it once the summer got started. The motor has been slow to crank when its hot, and I suspect that slave relay was the culprit. I have the control leg (Terminal 86) of the fuel relay connected to the ignition terminal of the Slave Relay because I could not think of any other ignition source to connect and didn't wan to run a separate wire all the way to the helm. My ket switch already has two ignition wires terminated on the "I" screw. I cant see how the slave relay may have affected the ignition terminal but perhaps it did. I've ordered a new fuel pump, slave relay and another fuel pump relay just in case.
I plan to double check the voltage of the fuel pump relay to confirm if its not getting sufficient voltage. If it is not getting at least 11.5 V then I need some guidance.
Relay wiring
86 - to Slave Relay "I" Terminal (16 AWG)
85 - To Battery Negative (16AWG)
87- To Fuel Pump Positive (12 AWG)
30 - Battery Positive - (12 AWG)
Fuel Pump Negative to Engine Block (ground)
What am I missing? Is is appropriate to terminate terminal 86 of the fuel relay to the "I" terminal of the slave relay?