Q: How do I tell the difference between an alternator issue and a starter issue?

asked by on

Just replaced the battery in the truck because it was dead and wouldn't start. After replacing the battery, the lights come on, the doors unlock, etc. The engine turns over but will not "catch". There is no "clicking" sound. The service engine light is on but has been on for over a year. How do I begin to figure out the next step and get an estimate? Is this a potential starter issue or a potential alternator issue?

My car has 100000 miles.
My car has an automatic transmission.

If the starter motor is turning the engine over at adequate RPM, then you definitely do not have a starter motor issue. Even if you had a bad alternator (and the alternator should absolutely be tested, certainly when you install a new battery because you want to be sure the charging function is working properly) that would not prevent the car from starting. So, if the starter is turning the engine over, but the motor won’t run, you have either a fault in the fuel or ignition systems, or the air induction system. To "quickly" determine if it is a fuel system problem, you can try introducing starter fluid into the intake while cranking and if the vehicle starts at that point that would be an indication that you have, at least, inadequate fuel delivery perhaps due to a fuel pump issue. The most efficient approach to getting this resolved is to just simply request a no start diagnostic and the responding certified mechanic will make quick work of this for you. At the conclusion of the diagnostic he will let you know of the fault and the cost to repair. Please let us know how we can best assist you to get your vehicle running properly.

Was this answer helpful?
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. How do I tell the difference between an alternator issue and a starter issue?

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: Check engine light on and bogs down

Hi there. Looking at the OBD-II trouble codes you provided us and your symptoms, it appears you have a torque converter solenoid or torque converter issue that is causing the sluggish driving and check engine light. The Powertrain Control Module...

Q: Got an oil change at Walmart, now car won't moves and stalls after stalling.

Hello. It would be hard to say what they did without seeing the vehicle. It is possible that they did not reinstall the air flow sensor correctly which would cause this. If it was not installed right it is...

Q: Q: Brake line leaking

First, you need to determine exactly where the leak is. It could be a line, a rear brake cylinder, master cylinder, caliper, hose, or cruise switch. If you are certain it is a brake line, the line will have to...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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.