Tach went out, Need assistance please
 

My tach recently went out after some oil was spilled on some wires below the oil filter. I did my best to clean all connectors but no luck, i have taken the tach gauge apart to look at the solder to make sure there were no cracks. I have cleaned the ground on the shock tower and the ground under the trail coil. Both coils spark so i know they are not out. I cannot find the solution please help!!

What car?

It's an 1986 rx7 n/a. Sorry about that