Where is the ignition module located in a 91 Jeep Wrangler?

In a 1991 Jeep Wrangler, the ignition module is typically located on the distributor. It's not a separate unit like in some vehicles. The distributor itself is usually found on the engine, near the firewall, but the exact location will depend slightly on the engine (4-cylinder or 6-cylinder). You'll need to look under the hood to find the distributor; the ignition module will be a part of it.