If the electronic fuel pump does not get 12 volts will it still turn on? Lets say I only have 5 volts to the pump, will it do absolutely nothing at all or will it still try to pump fuel? 1998 Hyundai Elantra
your pump should be getting 12 volts to operate properly. if not, there's no telling, and it probably won't work right. i would look into why it's getting so little voltage.. is the battery/alternator right?
I have a bad fuel pump or pump relay.
Between the relay and the pump I get a constant power on with key on and the light on my tester is only at about 50% brightness.
The light should go out after 3 to 15 seconds but it's constantly on.
So I'm thinking if the volts to the pump or so low this is why the pump is making no noise at all. But if it will try to pump even with low voltage but is doing nothing at all, it is probably the pump that went out.
I think with a constant on the relay is bad. both parts are bad if the pump should make noise with a low voltage.
I will be buying a volt meter later today to see what volts I'm actually getting.
i'm willing to bet your relay is bad. get that volt meter, as a light tester is really useless for anything but telling you if there is any power at all.
I just tested the open socket at the relay plug in and my light was super bright and tested at 12 volts. I went back to the plug and tested it and I got the same 50% brightness and it tested at 12 volts.. weird..
I installed the new relay thinking since it does not shut off after a few seconds that it must be bad, still the same problem.. Constant power and never shuts off like the relay is suppose to do?
Here's a image of what I am working with:
This clipped wires have always been that way since i got the car, not sure why they did that.
I would like to know what their reason was so I know if I should or should not correct there hack job..
The 2 wires that have been spliced do not have any power, possibly this wire is only for testing as the fuel pump test wire under the hood is a Yellow with red strip, same as the clipped wire, so I'm not sure if this even needs to be connected to the fuel pump as it's only for testing the pump? by connecting direct 12 volts.
I just replaced the Relay and still same problem. I replaced the fuel pump and still same problem.. The 2 spliced wires in picture are the power and ground to the actual pump and they are getting no power at all... I tested the Yellow/R wire from the from to back and I get a Ohm reading so there it no broken wires..
I made a jump from the Battery to the Yellow/R wire and I hear the pump come on, I also hear fuel pumping threw under the hood?
But the car will still not start???
I have about 4 gallons of fuel in the tank.
Something is not turning on to give power to the power wire and to allow the car to start?..
Any idea's? :help:
Before all this I drove to the store, got back in my car and it took 15 try's to get my car to start.
I shut the car off right away and tried to start it again and it started right up, I did this a couple times, started back up fine..
So then I drive to another store and do more shopping for about 1 hour, get back in my car and try to start it, same thing happen. Took about 15 try's to start the car and then I drove it home.
Next day it will not start. Tried to start the car 50 times and it will not start.
So now I did the above...
