[nperkins]

On my 90 miata, on the passenger fender right next to the ignitor is a two wire connector and one of the wires is corroded badly.

On one side is a blue and black wire, and the other side is a black/yellow and black wire, that looks like its going to a driver or heat sink.

What is this for? The only thing I can find in diagrams is that blue wires under the hood are for the wipers.

 

[nperkins]

Here's a pic I took...

 

[xander071584]

wipers or possibly wiper squirters... Id double check to make sure tho, I took my squirters of a while ago.

 

[nperkins]

Looks like its a Condensor..

But for what?

EDIT: Looks like:

Capacitor (Condenser)

The capacitor performs several functions. It prevents the points from arcing and prevents coil insulation breakdown by limiting the rate of voltage rise at the points. It's primary function is to provide for a rapid decay of the primary coil current. The capacitor also "third-harmonic" tunes the coil, raising the peak output voltage and increasing the secondary voltage rise time. This increases the efficiency and the amount of energy transferred to the spark plugs. If the coil secondary voltage rises too quickly, excessive high frequency energy is produced. This energy is then lost into the air-waves by electro-magnetic radiation from the ignition wiring instead of going to the spark plugs where we would like it to go. Voltage rise time should be more than 10 microseconds; a 50-microsecond rise time is OK. Conventional systems have a typical rise time of about 100 microseconds.