Which battery terminal do you take off first?

When disconnecting the cables from the old battery, disconnect the negative first, then the positive. Connect the new battery in the reverse order, positive then negative.” When you are replacing your car battery, It isn’t always easy to remember the order in which to disconnect and reconnect the terminals.

What happens if you disconnect the positive terminal first?

It can fall across either terminal and the car and nothing will happen. If you disconnect the positive terminal first and you drop a spanner, it is possible for it to fall across the positive terminal and any earth on the car, with spectacular and possible dangerous results.

How do you remove battery terminal clamp?

Step by Step Procedure to Change Battery Terminal Clamps
  1. Step 1: Disconnect the Battery. Start by disconnecting the battery cables from the battery.
  2. Step 2: Remove the old Connectors.
  3. Step 3: Clean the Battery Cables.
  4. Step 4: Acquire and Attach New Battery Clamps.
  5. Step 5: Reconnect the Battery Cables.

Can you remove battery post?

Loosen the nut that holds the terminal onto the negative post using a socket wrench. The nut will be located to the left of the terminal. Lift the terminal off the negative battery post. If needed, pry the terminal open with a screwdriver, or gently wiggle the connector until it loosens.

Can you use wd40 to loosen battery terminals?

There are a lot of remedies that may be used in order to get rid of rusted battery terminals; however, there are not many methods that are available to prevent them from corroding in the first place. That’s where WD-40 comes in! WD-40 can also be used to form a protective layer on the surface of the terminals.

Do I need to disconnect both battery terminals?

You only need to disconnect the negative battery terminal. You always remove the negative battery terminal first and put it on last. Modern cars will drain a good battery if left unattended for a long period of time. Current models of cars may probably not need disconnection of battery.

What happens if you don’t disconnect the negative battery cable?

But the complication is, whenever you disconnect the cable from the battery, you have to make sure it’s secured somewhere so it’s not contacting the ground or any of the positives. If the cable end is touching the negative terminal or is even in proximity to it, it could create a spark and cause a fire.

Can you just disconnect the positive terminal?

No, it won’t. You can disconnect whichever terminal you want, or even both, it won’t discharge. Whichever one you choose results in an open circuit so no current can possibly flow.

Will removing the negative battery cable reset computer?

However, disconnecting the battery will not only erase diagnostic trouble codes but also erase drivability, security and radio codes in many vehicles. Locate any codes and have them and the drivability learning procedures on hand before disconnecting the battery.

How long do I leave battery unhooked to reset computer?

An old mechanic’s trick for turning for temporarily eliminating certain kinds of driveability problems is to disconnect the battery ground cable for 10 seconds to “reset” the computer. Essentially, this trick erases the stored fault codes in the PCM’s keep alive memory and turns the Check Engine light off.

Will touching battery cables together to reset computer?

To prevent this, you may be instructed to disconnect the battery cables and touch them together. Connecting the positive and negative battery cables together for approximately 5 minutes will drain all of the capacitors in the computers and forces them to cold reboot.

Which battery terminal do you disconnect to reset computer?

Always disconnect the positive. I‘m sure removing the ground will have the same effect, but It’s good practice to pull the positive, as that is ultimately what you are trying to do disconnect the power.

How do you disconnect negative battery terminals?

How do I reprogram my ECM?

How do I reset my ECM?

What are the signs of a bad ECM?

Symptoms of a Bad or Failing Engine Control Module (ECM)
  • Check Engine Light Turns On.
  • Engine Stalling or Misfiring.
  • Engine Performance Issues.
  • Car Not Starting.
  • Poor Fuel Economy.

What happens if you unplug the ECU?

However, if the ECU is unplugged, it will retain any charge it may have even if you create a power draw someplace else in the vehicle. So you‘d need to wait a decent amount of time to be “sure” it’s drained. Some folks go so far as to unplug the battery and let the car sit over night.

Does disconnecting battery reset tune?

And removing your battery cables for safety precaution’s doesn’t remove the tune . It will reset everything as far as your air/fuel ratio so when you start it up again and let it do the idle adjustment . Then take it out for a normal drive so the Ecu can relearn your driving habits again.

Is it bad to unplug your car battery?

When you disconnect your car battery from the car, it helps prevent the electrical systems including the clock and on-board computer system from draining it completely. Therefore, if you leave the car battery unattended for longer period, then it might damage the battery and even need replacement.

Can a car lose a tune?

the tune is stored in non-volatile memory meaning that all the information will stay there even if the power is removed. If the dealer performs a flash upgrade it will erase your tune. the tune is stored in non-volatile memory meaning that all the information will stay there even if the power is removed.