Skip the auto shop - Our mechanics make house calls

Q: Car will crank but no start... Fuel pump not coming on. New pump, relay, etc. Will start when hot wire runs from pump wires to bat

asked by on

We have replaced the fuel pump and relays. Car will crank with hot wire from fuel pump wire harness to battery. ( Wires not getting connection) Tested with test light. When running, car will sometimes stall at red lights or stop signs. Replaced fusebox and car ran for two weeks no problems. but all of a sudden car wouldnt start again, only by hot wire.

My car has 174546 miles.
My car has an automatic transmission.

There are a couple of approaches to take here - either start from the battery and work "towards" the fuel pump, fuse box, ignition switch, fuel pump relay, and wiring connections in between. Or, as you have done, start at the pump with 12v, and move backwards towards the battery. This will require a GM service manual, or wiring diagram at least, with connection locations as well.

I would recommend having a certified technician from YourMechanic diagnose this starting issue, get an accurate assessment of damage and cost estimate for repairs. YourMechanic.com can dispatch a mobile, professional mechanic to your location for this repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  • Home
  • Questions
  • Car will crank but no start... Fuel pump not coming on. New pump, relay, etc. Will start when hot wire runs from pump wires to bat

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Leaking coolant - 2004 Chevrolet Silverado

Hi there. Depending on what edition of the Silverado you have the leaking coolant may be coming from the radiator overflow reservoir. It might also be a heater bypass tube that's damaged. The reservoir is used for overflow, as coolant...

Q: When I accelerate, loud ticking noise at low rpm, car jerks and stutters. It goes away at higher rpms.

The misfiring could be ignition or fuel related. If the plugs have not been replaced, on the timetable set forth in the maintenance schedule, that is certainly one possibly. Also, the plug wires could be tested. Diagnostic Trouble codes that...

Q: Car shaking

The car shaking is likely from a motor or transmission mount, but you could be having other issues, such as an engine misfire. I recommend that you have a mechanic, such as one from YourMechanic, run a diagnostic check of...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...