I choose "AIR". Bill's test sounds great, but I remember using a jumper wire at the plug near the hood alarm switch, that you jump from gnd to #3 or #4, and with the key on it would activate each solenoid one at a time, only once, then you have to turn key off and back on to do again. You can hear each solenoid click, in a quiet closed garage. A few years ago I bought an INOVA OBD 1 -2 tester. Finally read how to use it on a gen 1. There's one test that activates every solenoid in the car. It states that your going to hear a lot of clicks going on. Wife drove it yesterday, and reports that she heard a clunk when it went into OD. When it rains it pours. Love the car, but it's hate time ha ha.