Pull out the head unit, and check all the wiring. Every inch of it. And your headlights/head unit/speedo not coming on problem, check the fuseblock under the dash on the far left side. I remember when I hooked mine up (I had to re-wire literally everything, and I mean everything) my car wouldn't start, not even turn over. Checked all my wiring, replaced the fuse and bam, problem solved. The head unit had a bad ignition wire, causing it to arc out and pop the fuse. Btw I own a 98' as well.
Just A Sixxer!
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