Symptoms of a Fuel Pump Relay That's Indicating an OFF State The most common warning is that the engine will not start, because the fuel pump depends on the relay to get power. This pump is powered by the current needed to deliver fuel to an orifice for injection into the engine. Where, with the fuel pump relay stuck in the OFF position (to supply power to the fuel pump), this car cranks ok but does not start due no fuel being pumped out. about 70% of cases One of the main signs to be on the lookout for is no priming noise from the fuel pump, once you put in the ignition key. Ideally, the fuel pump should be emitting just a soft hum for around three seconds. If you dont have that sound, the relay could be stuck in the off state and like I stated preventing power to reach the pump.
Another method of locating a stuck relay is to test for fan operation by checking for continuity and voltage at the relay terminals with a meter. The fuel Pump relay should have 12 volts when the key is on If there is no voltage present at the pump when the key has been turned on, it may be possible that with age the relay is not closing the circuit so it remains in the OFF position. According to industry reports, 20% of no-starts due to fuel systems are the result of a bad relay.
One easy way to find a relay failure is by replacing it with another working relay of the same type Fuel pump relays, headlight relays and other components are often the same in many vehicles. If the fuel pump works after swapping the relay, then this confirms that your original relay was stuck OFF. This is a basic first diagnostic step used by automotive techs before going on to do more extensive tests and it results in time savings & lower labor costs.
A high-profile example was a recall of thousands of vehicles by a major auto company because their fuel pump relays could stick closed. The problem sparked a series of highly publicized no-start incidents, and the automaker urged dealers to replace the faulty relays right away.
Genius is one percent inspiration and ninety-nine percent perspiration-Thomas Edison. Pinpointing a fuel pump relay that is stuck can appear to be straightforward, however it regularly requires cautious testing and an organized methodology so the correct determination.
Replacing a fuel pump relay, is on the cheap side as far as repairs are concerned (usually $20-$100 depending on your vehicle). But, if you do not quickly tend to the problem, other problems like fuel pump failure are likely to develop which will skyrocket repair costs between $500-$1,000.
To sum it all up, if the fuel pump relay is stuck in the OFF position you'll see a no start condition where the fuel pump doesn't prime when you turn key on to on and check for battery voltage). Straightforward diagnostic processes will confirm the problem and prevent unnecessary repairs. If you would like to know how we can avoid problems with the fuel pump relay, please visit Fuel Pump-relay.