No surprise that the wipers don't work in a car that has been sitting for 25-30 years. Removed the cowl and wiper assembly. Removed the wiper assembly from the cowl and found it completely seized. It wouldn't budge even tapping with a hammer. Pretty easy to use rust release, scrapper and wire brush over 2 days and it is working fine. You need to soak it in the rust release generously over multiple times to start to get a little play then work the assembly until you get the full range of motion. The motor connecting arm needs to be removed to do this. Bench tested the motor and it work
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This is the condition I found under the cowl.
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I cleaned it and got this.
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I used a scrapper and then a wire wheel on a drill. There is a layer of black hard tar like substance that is covering the metal. I know this is some kind of rust protection material from 30 years ago. Question is should I remove it or just paint over it with anti rust paint?