09 750 Brute force wont start

[dustrunner]

The pump does have 2 wires that plug into the top of pump body connection. So I should cut the y/r wire and hook that to the brown / y wire while leaving the other wires in the connector still hooked together and plugged In ?

[ps2fixer]

Before cutting any wires, I'd run a test wire first. Like if it's a female terminal, you could pretty much just push bare wire into it, just don't short the two together. You'll have to figure out which one is ground vs power too. If it's male terminals, it's not so easy, guessing they are standard 1/4in spade terminals though, so worst case could buy some cheap ones at the store to make the test leads. I personally really hate suggesting cutting wires, I could probably make some sort of adapter/inline jumper to bypass the ECU signal, but we can worry about that after you get a chance to power the fuel pump and see if it will start off that. In theory it should as long as the fuel injectors are firing.

[dustrunner]

I took a wire and stuck it into the back of the plug with the relay still hooked into it. With w/r. To w/g and turned key on but still no pump work.

[dustrunner]

Just took multi meter ground to battery + to w/y = 0.0. Then + to w/g =7.72 then turn key on w/y = .02 and w/g= 7.27 v on dc 20 setting.

[dustrunner]

So am I jumping the w/r to w/g and also grounding something ?

[ps2fixer]

Weird, the relay is only has half the voltage, maybe the motor runs on a lower voltage or something. Jumping those two wires should have the pump run, even if it's under voltaged it would run slow atleast, so the ground through the computer might be at fault, but I'd think all the sensors would have issues since they share the same wire or the wire diagram just isn't showing the whole picture very well.

Searched real quick on this issue, first thread matches your situation pretty closely and they did the same thing as I suggested, jumped the two wires in the relay, fuel pump runs and bike starts for them. Guy found his fuel regulator was bad (lack of fuel 1/2 or more throttle), AND the ignition coil was weak/bad. Pretty rare to have two issues at once, but then again the effects he saw changed as he fixed stuff. Sounds like these machines had a lot of fuel related problems. I mainly wanted to validate jumping the relay would work, so in your situation you have a power delivery or ground issue for the fuel pump relay.

Also, did you validate if the fuel pump relay clicks when the key is turned on? You'll have to put your finger on it to be sure it's the right one, there's also an ignition relay the clicks at the same time based on that post. If the relay clicks, then things will make a bit more sense in my head, if not, then there's two issues, or the ground is the common factor.

https://www.mudinmyblood.net/forum/2...eshooting.html

Based on that thread, I guess the fuse box is another problematic spot, wire corrode etc. The wire diagram doesn't show me if the fuses get their power directly from the battery.

Had to look up wire color + pin location at the ECU, White wire that supplies power to the fuel pump fuse also goes to the ECU which is labeled as "8. Power Supply to ECU (from Battery)", so the power into the fuse should be battery voltage and that means the relay should be seeing the full ~12v or so. This suggests to me a bad connection like a corroded wire, corroded terminals, partially blown fuse, etc.

I also followed the wiring diagram to the other side of the pump (ground side) which also goes to the ECU to 3 pins labeled as follows.

11. Ground for Control System
33. Ground for Engine
42. Ground for Engine

Little more digging trying to find some sort of ground location page, and I found the REAL wire diagram.

Black/Yellow wire at the pump is fed off from the battery's ground cable that bolts to the engine (atleast that's how it's labeled). Can you do the same test but in reverse with your multi meter? Red probe to battery + and black probe to black/yellow wire for the fuel pump (harness side of course). You should be seeing full battery voltage. This will validate if you have a good ground.

• Ground test reading

Since it seems like the issue is related to the power delivery side. I have a bunch of tests for you to run to try to isolate which leg of wiring the issue comes from. Also be sure the battery is showing atleast 12v on the meter so I'm not thinking things a low voltage when it's the battery (use jumper cables and a spare battery or your car etc if needed for the testing, just don't short anything out =).

All of these tests are done with black probe to battery negative since the test above should validate the ground isn't the issue. The other probe will just be hopping fuse to fuse, you can probe the top of the fuses where the contacts expose through so don't need to pull them. Check both sides to be sure the fuse is good, let me know what the readings are for the following:

• Main fuse (30a) -
• Fuse Pump Fuse (10a) -
• Accessory Fuse (10a) -

With this full wire diagram, things make 100x more sense, the power doesn't run through the ECU like the other diagram suggests (stupidest diagram I've ever seen for that fact). Same with the ground, it doesn't run through the ECU at all.

Here's some more on the fuel pump relay if it's not switching when the key is turned on. This is the power source route for the switch side of the relay. All points should have full battery voltage.

Power wire side (black multimeter probe to battery neg for all these tests and use red to probe the wire on harness side)

• Starter solenoid (battery positive cable ends up here)
• Main Fuse (30a) (test both sides)
• Ignition switch (power from fuse is on white wire and can be tested, output is brown but requires the switch to be hooked up to test the brown).
• Kill switch (brown wire is input and can be tested, output is yellow/red and requires the kill switch to be hooked up to test)
• Fuel Pump Relay (power wire is yellow/red)

Ground side: (red multimeter probe to battery pos for all these tests and use black to probe the wire on harness side)

• Fuel Pump Relay (Brown/yellow wire) this should test good with the key on and the machine ready to start
• Pin 30 on ECU (brown/yellow), not expecting you to test this point, but figured I'd include it too, test would require to back probe the connector while hooked up
• Runs through the ECU to control the relay

** Note: Typically in a car when you turn the key on, the fuel pump runs for a few seconds and turns off and doesn't run again till the engine is cranked or running. I suspect this machine might be the same way, so you might have to stage the test (have everything setup to get readings), then turn the key on and see what the meter says.


Anyway, lots of testing for ya, might want to print it off and write notes down. Shoot me the readings and I should be able to trace it to a single wire/pair of contacts to inspect/replace/reroute. No clue how I missed the full wire diagram before, maybe because the electronics section labeled page for wire diagram just says Dummy Page and it's like 2 pages down further lol. Since this sounds to be a common issue for this model, I should build an interactive troubleshooter for this problem since I'm almost an expert on this system now lol. Only thing I'm not 100% sure on is how/when the ECU sends the fuel pump relay signal. Now that I'm armed with the data I really needed I think we can figure this out pretty easy, atleast for my side xD.



Anyway, here's the ECU pinout as well for more or less complete info for those finding this on google.




Here's a list of common problems for these machines. Seems like a lot of electrical and a couple mechanical issues to watch out for. Unrelated to your issue, but having a good idea what the machine is like and possible issues is generally good info to know.

http://forum.highlifter.com/Brute-Fo...-m4597505.aspx

[dustrunner]

THE fuel relay is the only relay clicking. I switched out all 3 plus the 2 that I purchased and they all click but only on the fuel pump plug. The voltage on the plug for the fuel pump is 12.45 with they off and 12.16 v with key on...that plug has 2 of those blk/y wires and both read pretty close to the same .

[dustrunner]

Also the y/r wire at the relay has 12.22 v with key on relay unplugged . while the w/g has only 2.03

[ps2fixer]

Interesting, so far. The only odd thing is the wire colors for the fuel pump relay, it should only have one dark wire which is Brown/Yellow, the starter control relays both have 2+ dark wires though. I wouldn't think this manual would have the same wrong colors in 3+ locations in it if it was inaccurate, book is a kawasaki branded manual covering 2008-2009 Brute Force 750.



Anyway, looking at the relays listed on the wire diagram, I don't see an ECU or ignition related relay, so I think that thread I got that info from was invalid or for different year (they said it's a 2008). Anyway, going off from what you found with the yellow/red wire and the fuel pump relay clicking that should mean the signal side of the relay is fine and it's the switching side with the issue (makes sense jumped the relay and no go since that's where the issue is).

When you get a chance, get the readings for the 3 fuses in my last post. Here's an image I found that shows the fuse probe spot to better illustrate what I was talking ab out.

[dustrunner]

Holding fuel pump in hand and jump from battery to positive of pump it spins making me think ground is ok ?

[ps2fixer]

Yea seems like the ground is good. Didn't know it was possible to back probe the connector on the fuel pump to supply power to it (bit risky doing that if you're unsure which is power etc, power wire -> ground wire = dead short). Multimeter test should work as well, but it's backwards logic for testing for power.

The white/green wire clearly is an odd value, with the 3 fuse tests I can get a good idea where the connector/wiring issue is. I'm kind of guessing right at the fuel pump fuse you'll see similar voltages and the other two fuses will test fine for voltage.

[dustrunner]

Fuel pump Fuse reads 4.42v on both sides

[ps2fixer]

How about the main fuse and one of the other fuses (doesn't matter which)?

We are on a trail!

[dustrunner]

Main fuse was around 12 and the other 2 fuses were 0 .0 maybe because they were e/g brk control and acc. DSCN2725.jpg

[ps2fixer]

According to this wire diagram, the 3 other fuses get their power through the main fuse. If two has no power and one has lower than expected, I think we found our bad wire.

I traced the brake control fuse (labled as actuator controller fuse) and it runs to the actuator controller, seems to make sense. It wires to the 4x4 actuator and engine brake actuator, whatever they do. Sounds like in it's current state, that's not working too.


Anyway, problematic wiring is between the white wire (main fuse output) to white/black & white/blue. Problem is, that wire goes to a LOT of stuff. We know which wire it is now, problem is finding where it's broken so a jumper wire can be installed and you have everything working like normal again.

We can go about this a couple different routes. I'd guess the issue is right by the fuse box, maybe there's a clear sign like a wire with green corrosion coming out of it. From what I can see, the fuse box should have a short wire length, then a connector. Need to do some testing at that connector to validate the issue is in the harness side and not the actual fuse box.

All of these tests are in Ohms test or beep mode. All of these should should connection on the main harness side of the connector.

White to White/Black
White to White/Blue

If those both test as having connection to each other, then we know the harness is good and avoids having to test the 20 other things the wire goes to. I also noticed I was mistaken, the acc fuse is powered off a different wire (brown) which is from the ignition switch and powered off the white wire. Just to validate, your brake lights work with the ignition switch on right? Your electric start I assume is working too, all that's powered off the brown wire and ultimately comes from the white wire. Kind of have a feeling the fuse box is at fault. That acc fuse should have power when the key is on if you wanted to reset that.

Related images for reference