I have dash lights but no mileage or shift indicator lights

It's just not a light bulb?

Common problem with GM trucks. No bulb to replace. Below is the test procedure. This is what I would need to do if it was at my shop first to know for sure but odds are you will need to replace the cluster. There are specilist that recondition those units and will exchange it for ypours but they do need to program your mileage into it first. A technician can retrive that info with a scanner. 1. Test voltage backprobed at the Instrument Panel Cluster (IPC) powers and ground. May use a headlight at disconnected IPC connector Key On, Engine Off (KOEO) to load the powers and grounds, then test voltage with a meter. 2. Replace the Instrument Panel Cluster (IPC). Must be programmed and calibrated.

Ok thanks for your help!