started with a speedometer & od going off and on-then brakes out -now won't start

Hello, "I don't think it's a battery issue" can be confirmed by having the battery tested! If you have no power and no clicking, you likely do not have enough power to crank over the engine. The battery could be low in charge, unable to sustain a load, or both. If you have a verified known good battery fully charged and tested to handle a load, then you'll have to look further into circuit protection, anti-theft issues, wiring issues, starter issues -- troubleshooting must begin to figure it all out. Low battery reference voltage and even possibly a charging system (alternator?) issue can result in your other symptoms -- speedometer issues and so forth. "Brakes out" sounds serious -- no electrical concern will cause brake "failure" -- but it's too hard to say without a hands on inspection.