Hi, was wondering why one of my negative wires is grounded to the battery tray? Plus, does anyoneknow where the body ground is on an 02 Sunfire? TIA

 

Sounds normal — the battery tray is often used as the chassis connection, so a negative lead bolted there is fine if the tray is solidly grounded to the car. On a 2002 Sunfire the main body ground is usually a braided strap or a bolt https://tropical-casino.com/ on the inner fender/firewall area near the battery or radiator support; there’s also a heavy lead to the engine block. To be sure, disconnect the battery, follow the negative cable to see where it ties in, or use a multimeter to check continuity between the negative post and the chassis. Clean paint/corrosion, tighten to bare metal, and use a star washer or proper strap if you add/replace a ground.