Thanks Marty , I had no idea what it does.I wasn't driving the jeep , just had the hood open with it running while I was listening for exhaust leaks from the headers.I had the jeep running for about 25 minutes so it was all nice and hot , and I happened to hear that thing clicking away.Unplug the wire and it stopped but there was no change to the jeep at all.

so it sounds like it is normal for that to make some noise , I have never heard it from inside the jeep.As long as the jeep keeps purring like a kitten I guess that solenoid works fine.

1996 Jeep Grand Cherokee 5.2 with mods.Hughes Air gap intake , 52MM TB , ford injectors, 2 3/4" lift, Doug Thorley headers , HID headlights with LED , HID fog lights , glow gauges , a few others