The coil with the double winding runs the fuel pump. The coil with the diode runs the idle control servo motor, the purge control solenoid, and the air temperature sensor. I have the factory service manual for this car and in it there is a very detailed description on how to test this relay. The particular check that this relay fails is: Connect the positive pole of the voltage source to pin #10, connect the negative pole of the voltage source to pin #8 and use a voltmeter across pins #4 and #5. The volt meter should show the source voltage. When I connect pins #10 and #8 The contacts can be heard as a "click" but the volt meter reads Zero volts. I perform this and the other checks inside my house using connectors I assembled. I purchased 2 brand new relays and both failed this very same check and were never installed in the car. They showed up bad. The relay has a cover which is not all that securely attached so I removed it from my relay to see what was inside just for the heck of it. I used an ohm meter to check the coils and all other possible junctions inside the relay and appropriate resistance was found. I then decided to remove the diode and measured its resistance in both directions. I found resistance way 1.5 million ohms indicating an open diode. That is my story and pretty everything I know about this relay. What problems there were with the 2 new relays I purchased I do not know for sure other than zero volts across pins #4 and #5 when there should have been 12 volts. Many thanks once again for all the responses. Ultimately I hope to repair this relay as there is only 1 company still making them, Standard Motor Parts and they are getting them out of China.