Skip the auto shop - Our mechanics make house calls

Q: 40 amp fuse blows when trying to start the vehicle.

asked by on

When I try to start my escalade the 40 amp IGN A fuse blows. I think it is the ignition switch. It is NOT the starter, as I have removed the starter and had it bench tested at o reilly and they said it tested good. What else could it be??

My car has 187000 miles.
My car has an automatic transmission.

You have a short in this circuit or a fault that is drawing excessive current. It could be the coil packs, ignition module, or a wiring fault (a short perhaps). This will require some effort with a volt meter to determine where the fault is occurring. If you would like some diagnostic assistance, I would recommend having a mobile, professional mechanic, such as one from YourMechanic, perform an inspection for any electrical problems.

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
  1. Home
  2. Questions
  3. 40 amp fuse blows when trying to start the vehicle.

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: My 2000 MR2 rear tail lights will not turn, also my power door locks constantly open and close by themselves while driving.

It sounds like you have a faulty light switch that may not be properly shutting the circuit to allow the tail lights to turn off. Regarding the door locks, this is often related to a malfunctioning door lock actuator, a...

Q: My car broke down on me and I check the fuse box and the fusible link had blown so bad that it blew the top off the fuse.

Hi there. From the description you have given, it must of been the main fuse that blew, causing your vehicle to break down. Your vehicle's main fuse is a high amperage fuse, it is capable of carrying a large electrical...

Q: What is minimum oil pressure at idle?

The minimum oil pressure at idle is only 5 psi (34.5 kpa). The minimum oil pressure at 2000 engine rpms is 35 psi (241 kpa). Both of these pressures are using a mechanical oil pressure gauge that can measure the...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.