Can alternator fry ecu?

The alternator mounting bolt is the ground for the alternator, if it falls off or loosens the resistance will shoot up and the resulting voltage surge will burn through the underdash fuses and fry the ecu (it may not blow a single fuse because the current has not overwhelmed them.)

What to do if your alternator has bad ground?

Place the red lead on the positive battery terminal (if possible dig it into the battery post, not the terminal). Place the black lead on the bad post of the alternator. Same thing as above, if the voltage is above 0.5v then examine the positive cabling for problems.

What causes an alternator to output low volts?

If the voltage at the battery and alternator don’t match. For example the battery reads 12v and alternator reads 14v. This means that there is an issue with wiring. While applying the same conditions as above.

How does an alternator affect the charging system?

The alternator is at the heart of the charging system of your vehicle. Alternator problems and charging system problems can affect your vehicle in different ways. You may notice: your ALT or CHARGE indicator light comes on, your engine is hard to start and cranks slowly, or doesn’t crank, your battery demands lots of water,

How can a battery damage an electronic control unit ( ECU )?

As such, circuity in the car drops the 12/13.5 volts to the 5 volt level that the ECU can handle. Now, if something goes wrong with this voltage-dropping circuity, or the alternator is defective and generating too high a voltage (which would also fry your battery in time), then too high a voltage may go to the ECU, thus damaging it.

How to get rid of a bad alternator ground cable?

1 Disconnect the negative ground cable from your car’s battery 2 Find out where the cable runs to and disconnect it from there 3 Attach the new cable to the spot where the old one was 4 Run the new cable back up to your car’s battery and reattach it

What can a faulty ECU do to a car?

The ECU, or engine control unit, is a major component of your car’s onboard computer. It’s used to regulate many systems and subsystems in your car’s engine, drive train and other major components. There are many symptoms that can be associated with a faulty ECU.

Where is the alternator ground on a car?

At first glance, it appears as though it’s a bunch of small steel cables braided together to make one big strap. This strap runs from the chassis located in your car’s engine block up to the negative terminal on your car’s battery, and it serves as a circuit for any and all accessories that might be connected to your engine block.

How can I tell if my alternator has bad ground?

Preform the same test with the positive side. Place the red lead on the positive battery terminal (if possible dig it into the battery post, not the terminal). Place the black lead on the bad post of the alternator. Same thing as above, if the voltage is above 0.5v then examine the positive cabling for problems.

Can alternator fry ECU?

Can a bad alternator cause ECU problems?

In some cars the ECU does have control over the alternator, rare but there are some. So yes it is conceivable, not really likely but conceivable. Doubtful that a car computer has any effect on an alternater but an alternator can ause computer problems.

How do I know if my ECU is bad in my Honda Civic?

Here are the most common symptoms of a bad ECU:

Check Engine Light stays on after resetting.
Car was jump started on reverse polarity.
Engine turning off for no reason.
Water Damage or Fire Damage on the ECU.
Apparent loss of spark.
Apparent loss of injection pulse or fuel pump.
Intermittent starting problems.
Overheating ECU.

Does the alternator power the ECU?

An alternator works together with the battery to supply power for the electrical components of the vehicle. These systems are controlled by the vehicle Engine Control Unit (ECU). As the vehicle demands more load the ECU sends a signal to the alternator requesting it to start charging.

Can a battery be grounded through an alternator?

Honestly you can be perfect just grounding from your alts ground to the negative of your battery (s). The engine is grounded through the alternator as it is and stock from the factory they have a dedicated ground to your frame/fender, and another ground dedicated to your starter motor.

Where to put black lead on bad alternator?

Place the black lead on the bad post of the alternator. Same thing as above, if the voltage is above 0.5v then examine the positive cabling for problems. Highly active question.

What should the voltage be on a bat alternator?

Measure the voltage across the battery and the big bat alternator terminal to alternator case. There are two things that you are looking for. The charging voltage should be between 13.9v to 14.4v. Also the voltage at the battery and the voltage at the alternator should be within 0.5v of each other.

Where is the ground point for an alternator?

Just go from either your engines alternator ground point to the negative of your battery or take a grounding point from your engine to the negative of your battery. Either way it will be a good grounding point.

Where does the alternator go on a truck?

The body of the alternator is ground. The alternator is mounted on the engine and the engine should have a ground strap to the frame. From the frame there is a ground strip to the battery. That’s a long way for a ground circuit. Works fine when the truck is new but after 30+ years you’ll have all kinds of corrosion on metal parts.

Where is the ground wire from the alternator?

The alternator is mounted on the engine and the engine should have a ground strap to the frame. From the frame there is a ground strip to the battery. That’s a long way for a ground circuit.

How is the ECU connected to the starter motor?

This in turn induces current in the ground wires going to the ECU; or in other words, the ECU shares some of the starter motor current.

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