My "new to me" 1974 280c is not charging. Mechanic said if battery light does not illuminate on dash when key is turned, before starting will not charge. Tried grounding the blue wire at the alternator and turning key, and no light.

Where do I check from here and how do I get the gauge cluster out? I can pull it out, but it only comes away about 1" and the bottom seems like it's still attached. Do I need to remove the mechanical gauges BEFORE pulling out the cluster? Thanks.