This relates to my previous post but the symptoms are head scratching even to my mechanic. A month ago I ran errands with no issues. Then my last stop i ran into the grocery store came out and nothing. No start no crank, but the car had power to the radio windows etc. I had found online that one of the relays can go bad. According to my mechanic the relays tested good. They can get it to start and run However it keeps blowing the fuel pump fuse. This is odd. So now what? Bad fuel pump, fuel filter clogged, a short? Has anyone here had similar symptoms on a vehicle.?
2005 Dodge neon Blowing fuel pump fuse
- Thread starter 97prizm
- Start date
Does it run a while before the fuse blows, long enough to do some testing while running? Is there a valve on the fuel rail where you can check pressure? When it runs, does it respond good to throttle and/or driveable without issue, like the fuel pressure is good?
I'd measure resistance between the pump power wire and ground, then again with it unplugged from the pump. The latter should be very high resistance if not open circuit since the pump's internal resistance is no longer in the circuit. This assumes nothing else is on the circuit. A wiring diagram would be helpful.
What else is on the fuel pump fused circuit? If nothing else related to starting is on it, then it is odd that it wouldn't crank either. I assume by "crank" we are talking about the starter spinning the engine. Do you have a bulk connector or two under the hood that might have come loose or suffered corrosion, or possibly rodents chewed on some wiring?
I wouldn't be paying this mechanic a lot if s/he can't figure this out with hands on the vehicle. I'm suggesting that if you don't want to DIY and the mechanic doesn't *owe* you further diagnostics without cost, then I'd take it to a different mechanic.
Make sure to use major brand replacement fuses, not some generic chinese brand which might be way over spec and risk further damage.
I'd measure resistance between the pump power wire and ground, then again with it unplugged from the pump. The latter should be very high resistance if not open circuit since the pump's internal resistance is no longer in the circuit. This assumes nothing else is on the circuit. A wiring diagram would be helpful.
What else is on the fuel pump fused circuit? If nothing else related to starting is on it, then it is odd that it wouldn't crank either. I assume by "crank" we are talking about the starter spinning the engine. Do you have a bulk connector or two under the hood that might have come loose or suffered corrosion, or possibly rodents chewed on some wiring?
I wouldn't be paying this mechanic a lot if s/he can't figure this out with hands on the vehicle. I'm suggesting that if you don't want to DIY and the mechanic doesn't *owe* you further diagnostics without cost, then I'd take it to a different mechanic.
Make sure to use major brand replacement fuses, not some generic chinese brand which might be way over spec and risk further damage.
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If the circuit is blowing the fuse than you have a short to ground either in the pump itself or in the wiring between the fuse and the fuel pump. Get a wiring diagram and see where all the circuit goes to. Are there other components on this circuit that could cause the fuse to blow? If so, start unplugging them and see if the fuse still blows.
I would probably start by unplugging the fuel pump and installing a five amp test light into the connector to see if it will maintain current and keep the light on. If the light goes out and the fuse still blows, then the short is further up the circuit. If the light stays on without blowing the fuse, then the fuel pump is the likely cause.
I would probably start by unplugging the fuel pump and installing a five amp test light into the connector to see if it will maintain current and keep the light on. If the light goes out and the fuse still blows, then the short is further up the circuit. If the light stays on without blowing the fuse, then the fuel pump is the likely cause.
On that new of a car, it will have a fuel pump relay.
Disconnect the fuel pump at the sending unit. Does the fuse blow, if yes, then wiring fault. If no replace fuel pump / sending unit and be done.
wiring faults blow fuses instantly in my experience. but disconnecting the pump is easy enough to do for a check
It's a bad pump or shorted pump wiring to ground. The relay is just an electrically operated high current switch. Pump power goes through the contacts. If its a low current fuse, it will be inline with the relay's coil not the pump's wiring. A high amperage fuse would be inline with pump's power circuit and very unlikely the relay would be at fault.
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So I got my car back from the mechanic yesterday and it was a mess. They found wiring that had rubbed and shorted causing the fuel pump fuse to blow. It also is the fuse for several other systems, not sure why. Once that was fixed the shop got the neon running but the fuel pump died. When they brought it in they said it had no juice in the battery, and it wouldn't take a charge. New battery. Then after going over everything, the alternator was also having issues with charging. So after two weeks and $1248.75 later the neon has a new wiring harness, fuel pump, battery, alternator, and oil pan gasket, which then I had them go ahead and change the oil. So hopefully this keeps my car on the road for a while.
