If your car will not start after a hot Temecula afternoon, the battery is the most likely cause, and that surprises people who expect batteries to die in winter. Heat is what actually kills them. Cold weather is just when a weakened battery finally fails to turn the engine over.
Sustained triple-digit heat accelerates the chemical wear inside a battery and evaporates fluid from the cells. A summer like this one is harder on a battery than any winter in this valley.
Telling the three common failures apart by sound
Nothing at all, no click. Usually a completely dead battery, a corroded terminal, or a bad connection. Interior lights that are dim or absent point the same way.
A single loud click, then nothing. Often the starter or its solenoid. The battery had enough power to engage the solenoid but the motor did not turn.
Rapid clicking. Almost always insufficient battery power. Enough to chatter the solenoid, not enough to crank.
Cranks normally but will not fire. The battery is fine. You are looking at fuel, spark or a sensor, and that needs diagnosis rather than guessing.
Why a jump start proves less than people think
A car that jump starts and then runs is not necessarily fixed. If the battery is at the end of its life it will strand you again, often somewhere worse. If the alternator is the actual problem, the car will run only as long as the jump-charged battery lasts and then die while you are driving, which is considerably more dangerous than not starting in a driveway.
Testing tells you which of those you are dealing with. Guessing does not.
The heat-specific ones people miss
Batteries that were marginal in June fail in August, not because anything changed that day but because the reserve finally ran out.
Corrosion builds faster in heat, and a terminal that looks slightly furry can be enough to stop the car entirely. It is worth a look before assuming the worst.
And a car that starts fine cold but refuses after sitting in the sun for an hour is behaving differently from one that will not start at all. That pattern is diagnostic information, so mention it.
What to check before calling
Look at the terminals for white or blue-green buildup. Try the headlights. If they are bright and strong, the battery probably has charge and the problem is elsewhere. If they are dim or dead, you have your answer.
Note whether the car has been sitting in the sun, whether it started fine that morning, and exactly what sound it makes. All three narrow it down quickly.
One thing worth knowing about battery age
Most batteries have a date code on the case. Three to five years is a normal life in this climate, and closer to three than five when the car lives outside in Temecula summers. If yours is in that range and the car is behaving oddly, age alone is a reasonable suspect.
Temecula Auto Repair & Transmission is on Jefferson Avenue in Temecula. Closed Saturday and Sunday.
