A few decades ago, not all vehicles were outfitted with tachometers.only high-performance sports cars had this as a standard feature. Fast forward to the present and you'll see a lot of drivers enjoying the benefits of having a tachometer in their ride's instrument panel.
An aftermarket tachometer gauge displays your car engine's revolutions per minute (RPM) so you'll know if your engine has been running at excessively high rates, which can shorten its service life. It is installed in manual-transmission vehicles as it tells you when it's time to shift gears, especially during braking and acceleration. Those who own a ride with automatic transmission, which normally isn't equipped with a tach, need to always keep tabs on the engine speed to prevent it from constantly running at high RPMs.
If you're outfitting your manual-transmission ride with a tach, you'd better keep in mind these few tips that will help make your DIY installation project safe and successful:
Before installation, adjust the tachometer according to the number of cylinders in the engine.
New tachometers can be adjusted to work smoothly with 4-, 6-, or 8-cylinder engines. You can change the settings by taking out the tachometer's back cap and setting the switches to match the number of cylinders your engine comes equipped with.
The tach usually has two switches. In a 4-cylinder engine, both switches should be down; in 8-cylinder engine, both must be up. In a 6-cylinder engine, one switch should be up while the other should be down. Read the instructions that come with your new unit to be sure of the adjustments that should be done on the tachometer's settings.
Make sure that your new tachometer is compatible with the spark plug wires.
There are new tachometers that are not compatible with solid-core spark plug wires. It won't be safe to connect these incompatible wires, so make sure first that you've got the correct wires by testing them using a multimeter. Replace any incompatible wire with the right one, and follow the proper installation instructions.
Test the wiring and electrical connections of the tachometer.
It isn't a good idea to drill mounting holes in the dashboard without checking if the tach really works. If the wires are correctly hooked up from the distributor and grounded, it will display accurate RPM readings when you rev the engine. You won't have a hard time grounding the wire because almost all portions of the car's frame are grounded to the battery by sturdy wires. You just need to trace those wires for you to find an appropriate attachment point.
Consult your vehicle's manual before attaching the tachometer's pickup wire.
Unlike the ground wire, this one has to be fed through a grommet in the passenger cabin to get into the engine compartment. The attachment point varies from one engine to another. Your repair manual will tell you where the suitable attachment point for your tachometer's pickup wire is. Follow the wiring setups for your ride as stated in the manual because a tachometer that isn't hooked up properly can melt, blow, or burn fuses.