You would just install it where the bad one is, as long as you are sure it's bad. Do you know how to test the old one with an ohm-meter? You can buy about any of the regular rectifier-type diodes at Radio Shack. There are two important parameters, voltage (needs to be grater than what's in your car, allowing for surges) 50V is fine, and current, greater than what you expect it to carry. If it's a sensor circuit a 1-amp diode is fine, if it's running light bulbs you probably want somthing bigger, say 5-10A. Price is not much different until you get to the really high power stuff. Put a lug on either end of it to match the old one, wrap it up and plug it in. There is a right and wrong way, the stripe end of the diode correlates to the direction of the "arrow" symbol on the diagram. Dave S --- In dmcnews@xxxxxxxxxxxxxxx, Soma576@xxxx wrote: > List, ... however i > need to know what type of diode to buy at radio shack for this purpose and > how to install it. > > any insights are greatly appreciated! > Andy > > > >