How to Wire an Ammeter into a Car

man holding an ammeter
What You'll Need
Safety goggles
Flexible gloves
Wire strippers
14 gauge red wire with eyelet terminals
Socket wrench
Screwdriver
What You'll Need
Safety goggles
Flexible gloves
Wire strippers
14 gauge red wire with eyelet terminals
Socket wrench
Screwdriver

Whether you own a performance sports car or a motorcycle, an ammeter can be a very handy gauge to have. This tool will help you determine whether or not your alternator and battery are working in harmony. These meters are used in many cars where there are multiple pieces of equipment that are dependent on the battery. Although some cars come with a very simple ammeter already installed, for those that make additions to their car or motorcycle, it is recommended that you wire up a more professional style of the meter to ensure that everything is functioning properly and your battery is staying charged. For some components, it is very important that they do not lose power, as items that incorporate the use of computers may reset to default settings if they lose power entirely, which could harm the performance of your motorcycle or car. By installing an ammeter, you can put your mind at ease that you are on top of your voltage needs.

Step 1 - Gather Materials

Before beginning your project, you should make sure that you have everything that you need so you will not have to stop what you are doing to look for a tool. You should gather a pair of safety goggles, gloves that permit hand dexterity, wire strippers, a red 14-gauge wire that comes equipped with eyelet terminals, a socket wrench, and a screwdriver. After you have gathered all of your tools, you are now ready to begin installing your ammeter.

Step 2 - Disconnect the Battery

Car battery

With your materials in a place where all tools and such can be reached easily, you should then locate the battery terminal on the positive side. The positive terminal is usually red and is indicated by a plus sign. Once you have located the terminal, you must then take either your socket wrench or screwdriver and disconnect your positive terminal from the battery post. This will help ensure that you will not shock yourself if any wires cross that are not supposed to.

Step 3 - Connect the Wire

Once you have your positive terminal disconnected from the battery post, you will then connect one end of the red 14-gauge wire to the positive battery post. Make sure that the eyelet fits snug over the post and will make proper contact once the positive battery wire is reconnected. After you have connected your red 14-gauge wire to your battery post, take the other end and connect it to your ammeter terminal. Remember to stay consistent with your connections because you don’t want your wires to cross. After you have connected both wires, you should hand tighten the nuts just in case you have to repeat any steps later on.

Step 4 - Connect the Ammeter to the Alternator

Car engine with arrows showing the alternator and battery

With your positive battery terminal now connected to the ammeter, you are ready to connect the next wire. Take your other piece of red 14-gauge wire and connect it to the other terminal of the ammeter. Once you have connected it to the ammeter, you will then connect it to the alternator terminal post. After this is complete, you can tighten all of your fittings and your project should be complete.