Q: 3 alternators replaced!

asked by on

My mechanic has no idea what's wrong. Went for a new alternator, it ran but won't charge battery. Then dash lights, running lights and brakes and do tag lights all went out. Replaced relay and alternator and again same issue. Battery won't charge ,alternators are going bad. Replaced again today to only have this happen again. Please please help me.

My car has 312000 miles.
My car has an automatic transmission.

This may suggest a failing voltage regulator. The voltage regulator is a unit that regulates the charging of the battery by the alternator. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. A common sign of this is usually the acid inside the battery boiling causing the battery to swell. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. 3 alternators replaced!

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: Stabilitrac light

It sounds like you are referring to the Stabilitrac light in your vehicle, which is a part of the traction control system. The traction control system monitors the steering and stability of the vehicle and engages when loss of traction...

Q: no crank with new starter, starter relay, battery, alternater.

If you tried jumping the contacts on the starter directly, then your problem is most likely a power or ground issue. The battery ground cable may not be making a good connection at the engine ground, or there could be...

Q: Seat belt lock not working.

Hi. If your seat belt lock is not working, then that is something that should be repaired as soon as possible for safety reasons. The seat belt should lock when the belt is moved at a quick rate as a...

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.