Q: 2012 Jeep Grand Cherokee replaces altanator, still won’t start. Brake seems locked

asked by on

Long story short, battery light came on while driving. Tried to make it home, jeep died. Had it towed. Replaced altanator, charged the battery overnight. jeep will turn on now, but won’t start. Brake feels really tight when I press it to try to start it.

My car has 103335 miles.
My car has an automatic transmission.

The brakes may feel stiff prior to starting the vehicle as the vacuum that exists in the brake booster when the vehicle is running may decrease when the vehicle is not running. Once the vehicle starts, the booster replenishes the vacuum assist and the brake pedal should feel normal again.

The issue of the vehicle not starting after charging the battery or after it sits for a period of time may suggest a failing voltage regulator that could be allowing the alternator to supply too much or too little amperage to the battery resulting in the battery never maintaining a consistent charge as it is designed to. 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. You may also smell a bit of smoke due to things potentially getting too hot. 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?
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. 2012 Jeep Grand Cherokee replaces altanator, still won’t start. Brake seems locked

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: low engine pressure/chk engine light

Hello, and thank you for writing in. There are two separate "low pressure" warning lights on the vehicle, the low oil pressure warning and the low tire pressure warning. It is safe to assume for now that you are speaking...

Q: Unknown leak problem and check gages light + Another Leak

The leak and cause of the light for gauges coming on could be the oil pressure sensor (which would be leaking and causing the loss of signal to the oil gauge. The leak on the passenger side floor is most...

Q: P0016

Hi...Diagnostic Trouble Code P0016 has many causes other than a failed camshaft position sensor. Other possible causes for Code P0016(https://www.yourmechanic.com/article/p0016-obd-ii-trouble-code-camshaft-position-a-camshaft-position-correlation-bank-1-by-jay-safford) to set include: the camshaft timing is wrong because the timing chain jumped teeth; the camshaft phaser is out of...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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.