Hi all. Looking for some advice on wiring issues (2010 FE450). I've just had the dreaded dead fuel pump failure, and it was definitely the pump as there was power to the plug but it wouldn't run when hot until it cooled down again. The pump has just been replaced and it was fine for the first ride, but when I went to start it another day I got the silent fuel pump treatment again. :cry:
This time, there was no power at the plug when I first checked it. Later when I tried again there was about 6V off load (the battery is fine at about 13v), then with a bulb across the pins the voltage would drop virtually to zero and the bulb would only be on very dimly if at all. Tracing this back, it was fine on the white-red wires where they leave the 4-pin plug on the starter relay (full voltage and would light the bulb normally), but not when it got to the fuse box on fuse 2 (back to almost no volts and no light). The resistance between those points measured about 5 ohms at one point and later about 20 ohms, so obviously a bad connection somewhere.
So the problem is between those two places, which on the face of it looks simple as they're only a couple of inches apart! But of course the white-red wires go down into the loom and go to various other places as well as coming back up to fuse 2. I've removed the sub-frame tank and had a look at the wiring around the shock and can't see any obvious damage, also I've tested again and it's now reading completely open circuit between the fuse holder and the starter relay plug, so I've obviously disturbed it while moving things about.
Thing is, no matter what I move I can't get any connection at all now, so it's hard to know where the problem is. I was hoping to bend or pull some part of the loom and get it coming and going, but no luck. So what I'm wondering is, does anyone know how far down the loom the white-red wiring coming down from the starter relay turns around and comes back up to the fuse box? That would give me some idea where to look and how far I might have to open up the loom.
The other thing is that the same wires also go to the power relay and the regulator, and I don't know at the moment whether the problem is before or after it splits off to the fuse box. If it was after that I could just run a new wire straight from the plug to the fuse box, but if it's before that then the regulator and power relay won't get full power (if any) either, which wouldn't be a good thing.
It would be useful to check resistance to those two items but a) I can't see where the plug is for the regulator to join the loom as the wires from the regulator seem to disappear under the tank (which I haven't taken off... yet), and b) I have no idea where the power relay is. Any hints on either? If I can get to those plugs and test the circuits it might help point to where the problem is in the loom.
Any thoughts gratefully accepted!
This time, there was no power at the plug when I first checked it. Later when I tried again there was about 6V off load (the battery is fine at about 13v), then with a bulb across the pins the voltage would drop virtually to zero and the bulb would only be on very dimly if at all. Tracing this back, it was fine on the white-red wires where they leave the 4-pin plug on the starter relay (full voltage and would light the bulb normally), but not when it got to the fuse box on fuse 2 (back to almost no volts and no light). The resistance between those points measured about 5 ohms at one point and later about 20 ohms, so obviously a bad connection somewhere.
So the problem is between those two places, which on the face of it looks simple as they're only a couple of inches apart! But of course the white-red wires go down into the loom and go to various other places as well as coming back up to fuse 2. I've removed the sub-frame tank and had a look at the wiring around the shock and can't see any obvious damage, also I've tested again and it's now reading completely open circuit between the fuse holder and the starter relay plug, so I've obviously disturbed it while moving things about.
Thing is, no matter what I move I can't get any connection at all now, so it's hard to know where the problem is. I was hoping to bend or pull some part of the loom and get it coming and going, but no luck. So what I'm wondering is, does anyone know how far down the loom the white-red wiring coming down from the starter relay turns around and comes back up to the fuse box? That would give me some idea where to look and how far I might have to open up the loom.
The other thing is that the same wires also go to the power relay and the regulator, and I don't know at the moment whether the problem is before or after it splits off to the fuse box. If it was after that I could just run a new wire straight from the plug to the fuse box, but if it's before that then the regulator and power relay won't get full power (if any) either, which wouldn't be a good thing.
It would be useful to check resistance to those two items but a) I can't see where the plug is for the regulator to join the loom as the wires from the regulator seem to disappear under the tank (which I haven't taken off... yet), and b) I have no idea where the power relay is. Any hints on either? If I can get to those plugs and test the circuits it might help point to where the problem is in the loom.
Any thoughts gratefully accepted!
