I have 02 Yamaha HPDI twin on my offshore 24, when I key on port motor, relay does not click, medium pressure pump does not run. I have known good relays and fuses. Any suggestions?
02 Yamaha 150 HPDI twins- Relay issues
- Thread starter Goatrljr
- Start date
You checked the fuses on the motor?. There are a few small ones and a big capacity one.
The next step is to test the power connections and the ground connection at the motor. Use a test lamp if you have one.
It is also possible that you have a problem at the helm with the ignition switch. When you turn on the ignition, does the gauge for that motor power up?
The next step is to test the power connections and the ground connection at the motor. Use a test lamp if you have one.
It is also possible that you have a problem at the helm with the ignition switch. When you turn on the ignition, does the gauge for that motor power up?
Fuses were good, ignition switch was good, Relay was not closing with key on. I was only getting 2v on double red wires w yellow strip that the red wire from the fuel pump plugs into. I stopped troubleshooting when I had 12v to yellow wire at engine wire harness.
Troubleshooting the harness on the motor isn’t the easiest thing to do. I was fortunate to have a spare harness and ecu from a good parts motor with a bad cylinder. I’m trying to get back on the water asap, so Im in the process of installing spare harness and ecu. There has been a lot of good info on this forum. I’ll revisit the “suspect harness on a rainy day. I’ll update soon.
Troubleshooting the harness on the motor isn’t the easiest thing to do. I was fortunate to have a spare harness and ecu from a good parts motor with a bad cylinder. I’m trying to get back on the water asap, so Im in the process of installing spare harness and ecu. There has been a lot of good info on this forum. I’ll revisit the “suspect harness on a rainy day. I’ll update soon.
Swapping the ECU can be a risky operation and is usually not advised but with my fingers crossed. The reason is that if there was a condition on the motor that fried the ECU, swapping a different one could cause the new one to fry also.
Note that you do not need a harness at all to power up and start the motor. You need a jumper connector that supplies 12v to the motor and a remote starter switch ( or just a jumper wire at the motor.
Did you measure the voltage that comes to the motor from the battery switch at the starter solenoid. That is the primary power source. Also check that the ground connection from the battery cable is good.
Note that you do not need a harness at all to power up and start the motor. You need a jumper connector that supplies 12v to the motor and a remote starter switch ( or just a jumper wire at the motor.
Did you measure the voltage that comes to the motor from the battery switch at the starter solenoid. That is the primary power source. Also check that the ground connection from the battery cable is good.
I had 12v at starter solenoid to ground on powerhead. I checked and cleaned battery ground and engine grounds that were accessible.
I agree with you on swapping the ecu could be risky if there was an issue that fried the ecu, but in this case I couldn’t start the motor without jumping the fuel pump because I was not getting the fuel pump relay to close. I felt it was more than likely a wiring issue in the engine harness or the ecu itself. Original issue was with key on, relay wouldn’t close, fuel pump wouldn’t run/prime. I compared to start sequence with operational starboard twin. On the operational motor key on, relay close, fuel pump primes. I checked voltage on double red wire with yellow stripe, which connects to red fuel pump wire- I had 12+ Volts. I was only reading 2v on non starting port motor at the same test point. I pulled the relays on the running starboard motor and I would get the same 2v reading as the port motor. I could be dead wrong but my thinking was key on sends 12v to ecu via yellow wire. Ecu sends 12volts to fuse block, relay closes. Fuel pump runs/primes. I also believe fuel pump ground provided by ecu?
I agree with you on swapping the ecu could be risky if there was an issue that fried the ecu, but in this case I couldn’t start the motor without jumping the fuel pump because I was not getting the fuel pump relay to close. I felt it was more than likely a wiring issue in the engine harness or the ecu itself. Original issue was with key on, relay wouldn’t close, fuel pump wouldn’t run/prime. I compared to start sequence with operational starboard twin. On the operational motor key on, relay close, fuel pump primes. I checked voltage on double red wire with yellow stripe, which connects to red fuel pump wire- I had 12+ Volts. I was only reading 2v on non starting port motor at the same test point. I pulled the relays on the running starboard motor and I would get the same 2v reading as the port motor. I could be dead wrong but my thinking was key on sends 12v to ecu via yellow wire. Ecu sends 12volts to fuse block, relay closes. Fuel pump runs/primes. I also believe fuel pump ground provided by ecu?
Most controlled devices connected by the ECU are done so by switching the grounds on and off and not by switching on the 12 volts as you might suspect.
I don't have a rigging manual for early model year yamis.
Without a wiring diagram, It is difficult to diagnose
There might be some info here
I don't have a rigging manual for early model year yamis.
Without a wiring diagram, It is difficult to diagnose
There might be some info here
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Update: I changed the engine wiring harness and used ECU from my parts motor. Relay closes and medium pressure pumps primes and motor starts & runs. Thanks for the feedback and help. I appreciate it.
I’ll revisit the harness and check it out, I hope to still find the root cause. I’m hopeful the root cause.