fuel pump fuse location

When the fuel pump is working, the carburettor float would stop the flow of fuel into the carb when the fuel level is attained. When pressure builds up, the pump piston would be held in the pressurised position and that would not allow the contact points inside the pump to meet and that would cut the current flow and stopp the fuel pump from working.

Keeping the fuel pump running would not flood the carb unless the float or needle valve is faulty.

In cases of accidents, if the engine had stalled and the fuel pump is running with a ruptured fuel line, fuel would continue to be pumped out and spews out of the ruptured hose, that would be a safety hazard.

Gee thanks for the kick in the crotch. Quite the contrary, I do understand many mechanical things. This is an instance where I am trying to figure out exactly how the system works. Maybe my problem is I haven’t given as much detail as needed. Yes, obviously the flow rate is set by the factory and when you turn the key off it no longer flows. However, with the switch powered up & the car not running, just on, the pump will flow fuel to the carburetor. Is there a check valve in the system that would stop it from flowing in this condition? This would be without the relay in the system. And yes, I know it’s a safety issue the way I currently have it jumped with the switch. I’m basically trying to get my car runnable while I sort out the electrical gremlin in the wiring. Can I the car with the jumper switch as a Band-Aid until I can find the source of my electrical woes?

whereis my fuel pump relay and my fuel cutoff relay

The fuel pump (main ) relay is located underdash just above the fuse box. It is a 7 pin grey box with brown socket points.

KHLow2008 - Bingo, that's what I was looking for I think.

Problem resolved?

your carb should stop the fuel from overflowing like KH said, if not your needle and seat or float is out of adjustemnt. Also the pump you have may have to much pressufe for your system. A carb type engine on ly uses 7psi MAX. so you woul dneed to add a regulator for it or disconnect the fuse you have going to teh relay so thepump won't run while you tinker with your electrical problem.

Hi,I tryed to change a bulb on the dash board and i made a short circuit applying voltage to the black wire on the dash board and blew the fuel pump fuse and after that i replace the fuse but now the car doesn't want to start. I checked to see if there was electricity in the fuel pump, fuel injector and spark plugs and there is electricity but the fuel pump does not work. what do you think is the problem?
do you think it has anything to do with that trigering the alarm or did i damage the fuel pump??

Hi nando39,

Thank you for the donation.

The fuel pump wiring is not connected when engine is not running and any wire shorting should not cause it to malfunction.

However a shorting of the ECU would cause the fuel pump not to work.

If the fuel pump does not work with voltage applied, then it is either bad or the wire circuit is open. I wuld suggest using a remote wire to test the fuel pump operations.

Did you check all the fuses? Another might be fused too.
Is the CEL showing for 2 seconds when ignition switch is turned ON?

Hi thanks for the reply. I applied direct voltage from the batt to the fuel pump and it worked, all the fuses are good,and all the ignition ligths comes up when i put the key, and what is the cel?

Hi nando39, CEL = Check Engine Lamp. Are there any sparks at the plugs? If yes, then you need to check the fuel circuit. The PGM-FI main relay might be intermittently failing resulting in no power supply to the fuel pump.

Test for power output to fuel pump for 2 seconds when igniton switch is turned ON.

HI,,yes there is sparks at the plugs and voltage on the fuel pump plug, but fuel pump not work.fuel pump only work only went I appied direct voltage.

P.S. SORRY,,, the wire that I aplied direct voltage was not the black wire on the dash boar was a white wire beside the black one behind the dash boar......that make the short circuit. can I aplied direct + OR - vlotage to the ECU to see if the fuel pump work? thanks

Electrical problem
1984 Honda Accord 4 cyl Two Wheel Drive Manual

Help, my honda accord keeps blowing fuel pump fuses. I have already changed the fuel pump and both fuel filters. any suggestions?

Hi nando39,

I am not sure which WHITE wire you are refering to as the power supply from the PGM-FI main relay to fuel pump should be Black/Yellow.

If the white wire is rather larger in diameter, then it should be power supply from the underhood fuse box which leads to the ignition switch. If that is the case, I believe one of the fuse is blown.

I would suggest checking
Underhood fuse box
1. Fuse # 46 (15 A )
2. Fuse # 42 ( 50 A )
Underdash
3. Fuse # 13 ( 7.5 A )

I would advise against shorting or applying voltage to the ECM without understanding the wiring system first.

most likely caused by faulty wiring. check harness connection at both the pump as well as the fuse box, ensure it is plugged in correctly and no damaged wiring.

here is a pic of the 2 wire that I applied + voltage and I blow the fuel but I replace the fuse but no want to run. white/silver dot and a black/white line. is there a in line fuse that Im missing? I check under the hook driver and pasenger side for fuses,all Ok .

hope you can help me

did you said a 50A fuse under dash board? i did not see a 50A,,, the only fuse I check are on the driver side,, passenger side and under the hook.

Hi nando39, No, the 50 A fuse is under hood Fuse # 42. Guess that is not the cause as it is the main power supply to the ignition switch.

From the connector can you please tell me the pin # location. I seem to have different wire colors for my diagrams.

I will do some research and see if I can pinpoint the cause. Ok, I now understand which 2 wires you are refering to. 1. A10 = interior light circuit 2. C4 = Reverse light going to the gear shift. From the circuit, there should be no connection to the fuse. From where did you tap the battery voltage to initially blow the fuse? What is the fuse location that blows initially?

98 Honda Accord 3.0 v-tec sometimes wont start, can this be the main relay (fuel pump) going bad? The check engine lite never comes on and there is no trouble codes.

Hi nando39,

I suggest we go back to the basics to understand what is happening. I would like you to provide me with some information with the following tests before we continue further.

1. Attach a test lamp to distributor Black/Yellow and turn ignition switch to ON. Battery voltage must be available.
If not, check Fuse # 1. If ok, test ignition switch black Yellow wire for voltage, must have voltage, if not switch is faulty.
If above ok, crank the engine. Voltage must be available. If not, ignition switch is faulty.
Sparks must be available at the plugs. If not, either distributor is fasulty or PCM grounding is inappropriate or PCM is faulty.

2. Attach a test lamp to PGM-FI main relay terminal # 2, ( Blue/Orange wire) Lamp must light up while cranking. If not, check fuse # 13 ( 7.5 A )

3. With ignition switch turned ON and while cranking, battery voltage must be present at terminal # 4.

4. Attach test lamp to PGM-FI relay terminal. turn ignition switch ON. Lamp must light up for 2 seconds.
Item 1, 2 and 3 above must be ok before this test needs to be done. If no power supply, relay is faulty.

Sure, it's possible but so are dozens of other things. You really need to do some testing during the failure to have any idea if you are on the right track or not.

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.



Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.


2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.


3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.

Thank for your time,,,I did all that, there is voltage on the distributor,spark plug,pgm relay and in the fuel pump plug. I even spray starting fluid on the intake and the car run for a second, but because there no fuel,it shut down. the starter cut relay has something to do?
I notice that during cranking the engine,all the dash board light star flashing even the security light, is that normal? or the immobilizer is engaged?
there is voltage on the fuel pump plug, but I dont hear the fuel pump humming went I put the key on, but if I applie direct voltage to the pump(not the plug) work. QUESTION,the fuel pump uses less voltage? dont know what to do, shoud I replace the fuel pump or not.. thanks

You need to test what is missing when it could nor start, fuel or ignition.

If it is fuel that is missing, the PGM-FI main relay can be the cause.

Hi nando39,

Dash lights flashing means it is not normal.
1. Faulty ignition switch. Try applying remote power supply to BlackYellow wire at distributor and start.
2. ECU fault. Immo fault would not allow cranking.

Thank you so much for your excellent help.I will Apply power supply to BlackYellow wire at distributor to see, I let you know.

P.S. I will not forget you, I will make another donation,,,,,,THANKS

is there a differents in a fuel pump relay and a fuel pump cut-off relay

Hi nando39,

You are welcomed and thanks for the appreciation, it makes my day ;)

Anything else feel free to ask.

Have a nice day and hope you get the problem solved.

Fuel pump cut-off relays are similar to inertia switches, they have the ability to cut-off fuel supply in case of an impact. A fuel pump relay is just a simple on/off switch type relay, which is only activated by the vehicle's computer system.

Hi there,,I applied direct + voltage to the BlackYellow wire at distributor and the dash board ights still flashing during cranking the engine and NO star and no noise from the fuel pump and blow the 50A fuse ander the hook. I did check(open) the ignition switch and look ok. I think may be is the fuel pump,if I spray starting fluid the engine star,and went I put the key ON there is voltage at the fuel pump plug but no noise.
So if not the fuel pump,do you think that is a ground problem? or definely the ECU fault?do I have to replace the ECU? thanks

Hi nando39,

If you suspect the fuel pump to be faulty, try unplugging the connector and crank to see if the fuse blows and if the dash lights flickers. Repeat this with the PGM-FI main relay unplugged if it is not the fuel pump. You definitely do not have fuel but the problem is, is it the control that is faulty not supplying power to the fuelpump or is it the fuel pump that is faulty.

Seems there is a major shorting somewhere otherwise the 50 A fuse would not blow easily. It is possible for the ECM to be faulty but ECM seldom produces major shorts.

I blow the 50A fuse went applying + remote power supply to BlackYellow wire at distributor and jumped the car. all fuses are good now but till same problem...

Hi nando39,

We seems to be going in circles.

If you have an ECM, I guess now its the time to test it.

By the way you mentioned that fuel is not present and the fuel pump worked if direct voltage is applied. Why don't you try applying direct voltage and try starting.

Hello again,,, I applyed direct voltage to the fuel pump(fuel pump work) engine only crank but no star.I repalced the PGM-FI relay and the ligths seem Ok now. I check all fuses driver side with a test light, on fuse #13 7.5A there no power, and went I put the key ON and pres the cluth the #2 wire on the PGM-FI plug there is no power.
PGM -FI plug test
1-PGM-FI #3 ground- yes
2-PGM-FI #7 voltage yes
3-PGM-FI- #5 voltage yes
4-PGM-FI #2 PGM-FI with pedal clutch in NO voltage
and No + power on #13 fuse driver side but fuse is OK.
Any idea whats wrong with this car?

Hi nando39,

Did you test both ends of Fuse # 13 forpower supply?

No power at fuse # 13 ( 7.5 A). Test if fuse # 11 and # 12 have voltage under same conditions as described.

If no to above, Check Fuse # 41 (100 A ) underhood.

Hi Guys,,,yes I test all the fuses on both ends and #11 & #12 have power when the swith is on. exept on #13 ther is no power . underhood #41 is good.

Hi nando39,

Fuse 11, 12 and 13 are on the same circuit and your diagnosis shows a faulty fuse junction box.

Without power from Fuse # 13, the fuel pump would not continue running after the ignition switch is returned from start.

Apply battery voltage to Fuse 13 and see if you are able to start.

Hi guys,I check all fuses all are OK. I have voltage on all the fuse box but not on the #13 7.5A only.
Also I check the fuel pump plug there are 5 wire;
(1) TESTED with a test light and KEY ON possition;
1- white/red line wire ---good + voltage
2-yellow/blue line wire---less + voltage
3-(2)black/silver dot wire--ground
4-black/yellow line wire----NO VOLTAGE

(2) TESTED the PGM-FI relay connector(key OFF) with a jumper wire on 4 and 5 NO voltage on black/yellow wire of the fuel pump plug.

Hi nando39,

The Black/Yellow wire for fuel pump runs through the fusebox before going to fuel pump at tank.

Fuse 13 has no power supply.

The fuse box has internal fault and is not transmitting power supply.

Hi guys,,,I changed the fuse box and the PGM-FI relay from my friend car but no star yet. I think At this point it had to be the PCM or ignition swith.

i need to know where the fuel pump is and how long it takes to change one