The most common method is to connect to the negative (-) side of the coil. This provides a pulse for each spark. However, be cautious; this is a high-voltage signal. You'll need to use a specific tach adapter designed to handle this. These adapters are usually readily available at auto parts stores and online. They step down the voltage to a safe level compatible with your aftermarket tachometer.
Important Considerations:
* Coil Type: The '94 Cherokee 4.0L uses a coil pack, not individual coils. Your adapter needs to accommodate this.
* Adapter: Absolutely essential. Don't directly connect your tach to the coil's high voltage.
* Wiring: Use properly insulated and appropriately-sized wire to avoid shorts and potential damage.
* Tachometer Instructions: Your tachometer should have specific wiring instructions, including the type of signal it requires (negative or positive). Follow these instructions carefully.
* Ground: Ensure a good ground connection for both the tachometer and the adapter.
Finding the Coil: The coil pack is usually located near the distributor (if it has one) or on the engine near the spark plug wires. It's a relatively easy-to-spot component.
In short: Don't try to directly wire the tachometer to the coil without an appropriate adapter designed to handle the high voltage. Using an adapter will safely convert the signal for your tach. Consult your tachometer's instructions for specific wiring details. If you're not comfortable with electrical work, seek the help of a qualified mechanic.
