1990 Dodge Ramcharger cant find bad fuseable link

There's a bunch of fusible links, and they all protect different circuits. They wouldn't all fail at the same time. Sounds like you have loose or dirty battery cables. Turn the headlight switch on, then twist the battery cable ends until the lights come on. Be aware there will be some small sparks so don't hold your eyeballs close to the battery. Batteries give off hydrogen gas which is explosive.

If the lights come back on, there's your proof the battery cables need to be cleaned and tightened.

Also check the small black negative cable that bolts to the body near the battery. Rust under that terminal will cause a bad connection. That ground wire affects all the circuits including lights and the starter relay. If you still haven't found the cause of the problem by now, holler back and have a voltmeter or test light handy.

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