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Fuel Pump Not Energizing After Horn Event. Relay Not Clicking


MaxSwell

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I hate to start another electrical thread, and have been reading all the wiring harness threads and testing various parts of the system, but I am trying to learn how to use a multimeter. Mine is analog. And all I know about electricity is that it is FM. (Fooken Magic). I need to figure out why oldster's fuel pump won't energize.

To find the bad spot, I'm supposed to remove the cable from the positive post of the battery, put the black lead (ground) from the meter on the neg. battery post, and measure voltage and resistance at suspect places along the harness. Right? The battery is charged and the engine cranks fine. Just no whine.

Everything was working fine (accept the horn - it's wires had been connected - broken fuse holder) before I took the wiring harness apart in front to replace the upper cowl support. All connections looked great and everything was connected properly. I had to buy a new in-line fuse for the horn and reconnect it. I turned the key and the horn started blaring non-stop. Shut off ignition and unplugged the horn. Deal with that later. But the fuel pump did not energize when I turned the ignition back on. I do not know if the fuel pump energized the first time because the horn had all my attention. Took all front wires apart again and sprayed electrical cleaner on both sides of all connections. Back together, fuel pump still does not work. Could the horn event affect the rest of the harness or the fuel pump ? This '01, the oldster, has 105,000 mi. I started to check the fuel pump but the service manual has me removing the air box and all ignition pieces so I stopped. Seems too much just to test the fuel pump. And I need detailed procedure to test the pump.

BTW, I have a VFRness and Rick's r/r to be put on the youngster (no r/r melting, burnt connectors, all looks perfect) bike as preventive. (The old gals r/r and stator failed and were replaced 17,000 mi ago. I'm hopeing they will last a while.) I should probably order a second VFRness for the oldster but money is tight and I've already spent $1500 for new bodywork.

I'm going out to disassemble the start/stop switch to see what it looks like. Back in a few minutes.

Terry

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The easy way to test the pump is to unplug the 2 pin connector under the tank - wire colors should be brown and green.

You can stick the 2 leads of the multimeter right into the connector and turn on the key, alternatively, you can stick one lead from the meter into the brown wire side of the connector and touch the black to chassis ground. Switch the bike on and look for a voltage about 12 (if negative, you have just flipped the leads from the meter, its all the same though). Make sure you are testing the side of the connector going to the bike, not the side going to the tank.

If you don't see any voltage at this connector with the key on, then your problem is in the switching circuit. If there is about 12 volts here, then your problem is with the fuel pump.

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The easy way to test the pump is to unplug the 2 pin connector under the tank - wire colors should be brown and green.

You can stick the 2 leads of the multimeter right into the connector and turn on the key, alternatively, you can stick one lead from the meter into the brown wire side of the connector and touch the black to chassis ground. Switch the bike on and look for a voltage about 12 (if negative, you have just flipped the leads from the meter, its all the same though). Make sure you are testing the side of the connector going to the bike, not the side going to the tank.

If you don't see any voltage at this connector with the key on, then your problem is in the switching circuit. If there is about 12 volts here, then your problem is with the fuel pump.

All Right! That I can do. Thanks v much.

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Fuel pump is on the same fuse, replace the fuse, then have a look at the horn itself, mine on the old girl had worn the plastic off the leads and kept shorting out when I turned the handle bars all the way, I taped it up with electrical tape and that fixed it. Or try shring wrapping the connectors then fitting them again. Then replace the fuse.

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Fuel pump is on the same fuse, replace the fuse, then have a look at the horn itself, mine on the old girl had worn the plastic off the leads and kept shorting out when I turned the handle bars all the way, I taped it up with electrical tape and that fixed it. Or try shring wrapping the connectors then fitting them again. Then replace the fuse.

I've checked all the fuses several times (under the seat and such). I'll do it again though. The problem with the horn is that it's on all the time when ignition is on. I cannot tell from fiche if there is an inline fuse for the horn right up front. Thinking lately the fuse may be left over from an old install of a cig lighter socket. What diff. would that make. A fuse for a lighter on the horn wires. I'll try leaving the fuse off for the horn to see if that makes a diff. No possible way for this fuse to be for the fuel pump. This was hanging loose under the front cowl.

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Fuel pump is on the same fuse, replace the fuse, then have a look at the horn itself, mine on the old girl had worn the plastic off the leads and kept shorting out when I turned the handle bars all the way, I taped it up with electrical tape and that fixed it. Or try shring wrapping the connectors then fitting them again. Then replace the fuse.

Are you sure about that? I can pull the horn fuse (also with turn signals) and the bike will still start. A quick check of my mostly disassembled '98 and I don't see an inline fuse for the horn or any other circuits in that vicinity. As far as the horn goes, did you play with the switch to check if it was stuck?

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This may sound strange but I recently had the same dead fuel pump issue on my 99 after doing some electrical work. So I started to look at the relays that are on that circuit ( one in the rear on the right side of the bike and one at about amidship on the same side) ... I wS just about to start jumping these relays when I remembered something about fixing a stuck relay with a good whack from a screwdriver handle. So I whacked the middle one 3 or 4 times with a good size screwdriver and whammo she fired right up. Not very scientific I know but effective in my case and really easy to try once the plastic is off. Good luck!

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A relay is nothing more then a remote controlled light-switch in your house.

When you power a relay the switch goes to connecting mode, same as you turn your house lights on with your hand.

When you remove the power to a relay then the contact opens en the house light goes off.

This to give you a good idea what a relay is and does.

So when you make contact with your ignition-key, you power the relay and the current should flow to your fuel-pump.

Ergo measure if the fuel-pump is getting any voltage.

If it does the fuel-pump is probably broken.

If it doesn't, then measure the input of the relay to see if there is voltage to see if there is any voltage at all.

If the relay does get voltage, then the relay is broken.

If the relay doesn't get voltage then a fuse or some wiring to the relay has a problem.

It's basically nothing more then follow the line where the current stops flowing.

The same as with a river, there is a problem at the bottom (fuel-pump) then follow the stream until you find the point where the water (voltage) stops :laugh:

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According to my wiring diagrams (I have both Oz 2001 model and rest of world, 98-99 model, and this part of the wiring doesn't differ) there are two relays and the PGM/FI involved in the fuel pump circuit.

You have a Black/ pink wire from the fuse which is switched by the 'Engine Stop' relay to a Black/white wire which both energises and is switched by the Fuel Cut Relay which is controlled by the PGM/FI, the output of this relay is the brown wire to the pump The black/white wire feeds to nearly all devices in the fuel circuit, injectors, fuel pump, ignition coils, intake duct control solenoid valve and a feed back to the PGM/FI.

So if 12V is missing from the Brown/Green wire at the two pin plug/socket feeding the pump there is plenty to explore :cool:

There is no indication of where the relays are located on the bike but the wire colours may give a clue and no connection between horn and fuel circuit although the fuses are shown beside each other on the wiring diagram. If you need to I can draw a circuit but just a bit short of time at present.

Good luck, a bit of relay tapping sounds like a good idea on a bike with the mileage yours has.

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Thank you all. Sounds like I'll have a busy day today. I've got my fingers crossed. And I'm going to sacrifice a quart of oil to the Motorcycle Gods.

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Ok. Here is what I've done so far.

1) Tested both the fuel cut relay and the engine stop relay. I did that by unplugging each from the problem machine, one at a time, and plugging them in on the bike that has no fuel pump problem (that is the bike that needs new rear brakes). In both instances, the fuel pump energized. So it's not the relays, CORRECT?

2) I disconnected both the connectors under the fuel tank. Blue connector (grey/black wire and green wire) goes to the front of the tank. The white and brown connector (brown and green wires) to the fuel pump. Put my mulitmeter leads into the brown connector and switched on the ignition. No voltage, with the meter set at 50 and set at 10.

So if it's not the fuel pump (very glad for that; very pricy), and not the relays, what can it be? Does that mean the ecu has a issue?

I do not know where to go from here. Haul it to the dealer? That could be pricy also.

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Just to check, is your meter set to measure V DC? There may be a symbol of a line with some dashes under it. The sideways S is for measuring AC, and will read 0 if you measure a DC source like the bike. The analog meter may not display negative voltage, so you may want to check, swap leads and check again just in case there's a lead swapped somewhere.

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I double checked and swapped leads. My analog meter was set to DCV.

Nada.

Thanks for the suggestion Dawson.

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Sorry for the obviousness. Just something I see kinda often with guys learning to use meters.

There's no way the horn and fuel pump wires got swapped somewhere, is there?

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No dice on the horn. I thing the horn was a red herring. I realize I connected old wires for a cig-lighter-type outlet to the horn. Weird I know but I guessed wrong on a wire hanging loose. I undid it and found the real horn wires. I only brought it up to see if that mis-wiring could have affected something in the rest of the harness. I AM a bald-a$$ rookie for meter use. So I appreciate the not-so-obvious. esp. the swap leads re analogs don't do negative. I did not know that. I was curious to see where the needle went though. Not much room over there. Maybe I was expecting a big minus sign. :tongue:

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Sometimes when reconnecting big connectors the pins and sockets don't line up properly and one can get pushed back out of the plastic shell. Might be worth taking a look at the back of it to see if you can see any wires sticking out farther than the rest.

All I have here is a gen6 wiring diagram, but if they're close, the power runs through the kill switch to the engine stop relay. That means that with the kill switch in the run position and the black lead of your meter on the frame, you should measure 12v on both leads of the kill switch. If it's not there, your problem is before. On this diagram it goes battery to RR, then kill switch, then engine relay. If you have 12v on one lead of the kill switch, the problem is there. If you have it on both sides, there's something wrong between the kill switch and the engine relay.

The engine relay coil completes its path through the bank angle sensor, so that could be messing with you too.

That's all the coil side of the relay, which is what controls its clicking.

There's a few connectors in the mix too, but you should be able to trace the power all the way through to the engine relay coil when the key is in the on position.

That's all off the gen6 diagram, so you may want to double check the paths against the proper schematic.

Good luck!

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Forgot to check. can you measure 12v at the battery? There are a couple of fuses in the meter that will give you 0v readings everywhere if they go. It's a good idea to zero an analog meter whenever you use it as well. Set to ohms, touch the leads and turn the zero dial until the needle hits the zero ohm mark. This also proves that your leads are good. It sucks when they're not...

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Fuel pump simplefied schematic

This is a simplified schematic of the fuel pump switching circuit. Note that the Black/White wire goes to many other systems not indicated on this diagram. Engine stop sensor = bank angle sensor

Ensure battery is fully charged.

I don't know if your meter is capable of measuring continuity or resistance, so I will assume you have a very simple Volt/Amp meter. If you get a 0v reading at any of the points below, you can stop testing and address each issue until you get 12v at that particular point. Sounds like the bike does crank over from your earlier post, so I skipped some of the earlier tests which wouldn't help us solve the problem. For example, I assume the Key switch is functional...

This is how I would troubleshoot this circuit:

1. Attach black (negative) lead of meter to chassis ground or negative battery terminal. You won't need to move this for most of the testing and if you do I will indicate it.

2. Turn key on.

3. Check for 12v -> Red lead goes to:

A. Black/Pink wire at Engine Stop relay

IF 0v - Check Fuse 2 or wiring to relay from fuse box

B. Black/white wire at Fuel Cutoff relay

IF 0v - Check Fuse 4, Ensure that Kill Switch is in Run position, Check wiring between Engine Stop relay and Fuel Cutoff relay

4. Turn key off

5. Attach positive lead to Brown wire AT Fuel Cutoff relay

6. Switch key on an watch for momentary 12v signal.

IF you do see 12v here, check the Brown wire for connectivity to the Fuel Pump connector and the Green Wire for connectivity to Chassis Ground.

If your meter can perform continuity/resistance checks then determining if the wiring is sound will be much easier. If, for example, you wanted to check the continuity of the kill switch circuit: With the key OFF, attach one lead to White/Black stripe wire at Fuse 4 and the Solid Black wire at the Engine Stop relay.

I hope this isn't too confusing. I may have glazed over some details or made incorrect assumptions about your background knowledge.



Oh, BTW, since the ECU does play a certain role in this, you may want to clean and re-seat the main connectors there as well. I'm not sure how resistant the ECU is to electrostatic discharge, so I wouldn't touch the pins on the ECU side of that connection though.

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Forgot to check. can you measure 12v at the battery? There are a couple of fuses in the meter that will give you 0v readings everywhere if they go. It's a good idea to zero an analog meter whenever you use it as well. Set to ohms, touch the leads and turn the zero dial until the needle hits the zero ohm mark. This also proves that your leads are good. It sucks when they're not...

Yes. Looks like it is 13+. I did zero the meter at first. I'll do it every time now. But I look at it and when turned on, it is right on zero.

All the wiring harness connectors look great.

When I take them apart to inspect, I blow them clean, they do not look corroded, and carefully apply Ox-Gard. Conductive and anti corrosive, slightly abrasive for improved contact.

Rechecked all fuses (I counted 10), and even used a paper clip to jump the service plug to see if there was fi blink code. The fi light comes on, stays on, and does not blink. Checked the stop/start switch interior. Clean as a whistle.

Now I'll read MadScientist response.

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This is a simplified schematic of the fuel pump switching circuit. Note that the Black/White wire goes to many other systems not indicated on this diagram. Engine stop sensor = bank angle sensor

Ensure battery is fully charged.

I don't know if your meter is capable of measuring continuity or resistance, so I will assume you have a very simple Volt/Amp meter. If you get a 0v reading at any of the points below, you can stop testing and address each issue until you get 12v at that particular point. Sounds like the bike does crank over from your earlier post, so I skipped some of the earlier tests which wouldn't help us solve the problem. For example, I assume the Key switch is functional...

This is how I would troubleshoot this circuit:

1. Attach black (negative) lead of meter to chassis ground or negative battery terminal. You won't need to move this for most of the testing and if you do I will indicate it.

2. Turn key on.

3. Check for 12v -> Red lead goes to:

A. Black/Pink wire at Engine Stop relay

IF 0v - Check Fuse 2 or wiring to relay from fuse box

B. Black/white wire at Fuel Cutoff relay

IF 0v - Check Fuse 4, Ensure that Kill Switch is in Run position, Check wiring between Engine Stop relay and Fuel Cutoff relay

4. Turn key off

5. Attach positive lead to Brown wire AT Fuel Cutoff relay

6. Switch key on an watch for momentary 12v signal.

IF you do see 12v here, check the Brown wire for connectivity to the Fuel Pump connector and the Green Wire for connectivity to Chassis Ground.

If your meter can perform continuity/resistance checks then determining if the wiring is sound will be much easier. If, for example, you wanted to check the continuity of the kill switch circuit: With the key OFF, attach one lead to White/Black stripe wire at Fuse 4 and the Solid Black wire at the Engine Stop relay.

I hope this isn't too confusing. I may have glazed over some details or made incorrect assumptions about your background knowledge.

Oh, BTW, since the ECU does play a certain role in this, you may want to clean and re-seat the main connectors there as well. I'm not sure how resistant the ECU is to electrostatic discharge, so I wouldn't touch the pins on the ECU side of that connection though.

I'll sure give it a try. copy / print / out to the garage tomorrow morning.

Thank you v much.

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You'll get some great skills out of this. Ultimately testing of DC wiring systems is a simple endeavour and only appears complex because it's hard to visualise which wires go where.

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You'll get some great skills out of this. Ultimately testing of DC wiring systems is a simple endeavour and only appears complex because it's hard to visualise which wires go where.

We all expect a " TROUBLE SHOOTING YOUR FUEL PUMP" seminar at TMac .....

:goofy:

Hang in there Terry you will figure it out.

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Had a similar issue recently. Check the fuses with you multi meter! No continuity. Replace it!

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and make sure they are pushed in all the way...

Do not ask how I know... :unsure:

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