Not both. Disconnect the NEGATIVE post.
You should connect and disconnect the negative post first. This way, if your tool touches ground when you work on the positive post, you don't short circuit the battery.
disconnect the wires starting with the negative post first. there is a clamp holding the battery down at the base of the battery in the middle of the long side. loosen the bolt and tilt the battery out.
disconnect the positive battery post and wait five minutes , then reconnect battery. The light should go out
There are two types of battery cable connections. The clamp type connects to a post on the battery and is held in place by a nut and bolt which squeeze the sides of the clamp tightly around the post. Disconnect by loosening the clamp's nut and then wiggling the clamp off of the post, start with the negative cable (black one). The bolt on type (sometimes referred to as 'side terminal' type) is bolted directly to the battery. To disconnect this type, simply unbolt it and remove the cable end from the battery. Again, start with the negative (black) cable. If the goal is not removal of the battery, but disconnection of power to the vehicle for servicing, disconnection of only the negative (black) cable is sufficient.
Disconnect the negative battery cable.
Best to unplug it and then disconnect it from the battery. Reason being is that if you disconnect it from the battery first you will create a spark. That spark could ignite any fumes from the battery.
Yes, you better disconnect the negative battery cable.
If working on the electrics of a car then it is a sensible precaution to disconnect the battery.
You disconnect your negative (-) battery terminal and connect one of the meter's probes to the (-) battery cable and the other terminal to the (-) battery post. Set your multimeter to mA/A and select DC.
Connect the positive (+) Red cable from the charger to the positive (+) post of the battery. Now connect the negative (-) Black cable to a metal part of the engine. Do not connect to negative battery post. Plug the charger in. Unplug the charger before removing the cables. Disconnect the negative cable first.
The negative cable can be removed from the post under the hood that is attached to the left wheel housing. The negative cable is only about a foot long and is connected directly from the upper post to the negative post on the battery. It would be best to remove the battery completely if it is going to be stored for a lengthy period. If you place a trickle charger on it, eventually the battery will require water to be added to it.