on my hitachi ex120-2 The fuse for the ec motor blows as soon as I turn the ignition key on. I traced the wires from that fuse to the ec relay. They all seem ok. I tried the wiper relay in place of the ec relay but still blew fuse. next to the wire at the fuse is a thick red wire which looks fine, I traced back to the ignition switch. Can the problem be in the ignition switch?
It could also be a wire to wire short inside the wire loom that you don't see, not just from rubbing around corners or through clamps.
No will not be ignition switch. The fault current will be caused by something down stream of the EC relay. If that circuit diagram is correct that relay is supplying power to the that power controller card. It is not normally easy for that card to create a short so the most logical place i would start looking was down stream around the ec motor on the engine. If you unplug that wiring loom at the card or down at the motor and try again with new fuse. if the fuse does not blow you just narrowed down where the problem is.
Thanks guys, what I might have forgot to mention was if I plug in Ec motor and unplug the Pvc the fuse doesn’t blow.
What are you calling Pvc? [Power motor motor relay]?? The board in the middle of the circuit appears to have a fuse for each of its functions. So the fuse that is blowing is probably only to do with the EC Motor. When ignition is on power is available to the top of the ec motor relay through the fuse that blows. The power motor motor relay card below then energizes the relay above and allows power to flow into the card which is then used for the ecmotor which comes out further down on bottom right. So you need to disconnect the ec motor but leave power on the card and relay. If the fused dose not blow the problem is probably in the ec motor. These motors will have very low ohm wingdings even when good, so they turn into a short very easy if they over heat and burn the coils. A good multi meter can be used to check them.
Thanks 007. pvc -pump and valve control. Could the ec motor be bad even if the LED is flashing?
If the fuse is blown the motor will not validate in a response check..
Hook a light bulb in place if the fuse... you can then wiggle wires and see if you can make the light go dim... bright means short, dim, means ok.. but will make it so you can troubleshoot without replacing fuses.