1. Its got two wiring connectors going to it.
2. Its On the Driver side, front, of engine compartment, mounted in front of driver side front wheel well. Some of the wires are pretty hefty
3. About 3" x 5" mounted in a diagonal fashion (i.e. slanted, not perfectly vertical or horizontal)
4. secured by 4 screws to inside of fender wall
5. "CLICKS" when i apply 12V signal to the starter solenoid
6. Looks pretty major and ominous; please dont confuse with the AC relay box that houses two relays and sits on top of the right wheel well hump. This one is about 6 inches forward of it near the headlight area.
7. Need to know because i Am troubleshooting my faulty ignition circuit

Are there any kind of numbers on it?

Sounds like a glow relay.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician