Why would my battery light and brake light come on at the same time?

Why would my battery light and brake light come on at the same time?

The battery light will come on when the event that the battery is no longer being charged. The ‘E’ brake (parking brake) light comes on when the fluid is low in the master cylinder or there is a pressure difference in the brake system. Have the alternator checked and see if the battery cables are tight.

Can an alternator test good but still be bad?

The only way to know if an alternator is good or bad is to bench test it on an alternator test stand. If an alternator can produce normal voltage and current during a bench test, the problem is not the alternator but something else on the vehicle.

What can mimic a bad alternator?

Testing at the Battery Start by checking your battery terminals. Loose or heavily corroded terminals can mimic the effects of a bad alternator.

How do you know if your alternator is shorted?

Disconnect the big main cable to the alternator and see if the short goes away. If it does, then use your meter to measure the ohms between the alternator post and the alternator case. You should have continuity in one direction and if you switch leads you’ll have no continuity.

How do you tell if it’s your battery or your alternator?

If your engine won’t turn over or takes far longer than usual, it’s time to grab the jumper cables and attempt a jump-start. If your engine starts and stays running but won’t start again later, it’s likely a battery problem. If your vehicle immediately stalls, it’s probably a bad alternator.

Can a bad battery act like a bad alternator?

Other times, however, a dead battery could be a sign that your alternator is malfunctioning. A bad alternator won’t sufficiently charge the battery while the engine is running, causing the charge to deplete faster than usual. If you jumpstart your car and it stays running, your battery may need replacing soon.

Can a battery short an alternator?

A high amperage dead short from the main output wire to ground can be caused by an alternator with a rectifier in it. If you don’t disconnected the batteries, it will be hot all the time.

What happens when a battery is short circuited?

If it is a battery that is shorted, the battery will be discharged very quickly and will heat up due to the high current flow. If a charged, high-voltage capacitor is short circuited by a thin wire, the resulting huge current and power dissipation will cause the wire to actually explode.

Why is my battery and brake light on?

Should be a black wire bolted on the back side of the alternator. If its loose or disconnected it could be causing your intermitent problem. Also check your main battery ground is tight, fromt he battery to intake manifold. Re: Why is my Battery and Brake Light on????? (Jay97240Sx) I got these two lights one night on a road trip.

What causes a battery light to come on after an alternator is installed?

The most common is, again, a loose connection either with the control plug (aka “relay” plug-in), charging line connection, or the ground. The other is a blown fuse or defective connector or relay, which could have been broken or shorted when the alternator was installed or on the first start-up after its installation.

Can a battery be defective out of the box?

Sometimes, batteries are just not as good as they are manufactured to be due to hidden defects or a longer-than-usual shelf wait before being purchased. Similarly, alternators can be defective out of the box, especially if they’re refurbished or rebuilt.

How can I test my car battery relay?

Assuming all fuses are fine, you can test relays by swapping them with others of the same part number (many vehicles will have two or three of the same relay running various components) or by testing the relay itself via continuity and resistance methods. The following two tabs change content below.