I have a 74 duster 360 that I got the wiring harness out of a 74 valiant. I have this relay that the cover is gone and I have no idea what it is for- makes it hard to order one. Anyway- it is located really close to the ignition box and ceramic ballast. It has a total of 4 prongs but has two sets of plugs hooking into it. One is a 3 prong plug and the other is just one. The 3 prong plug has one yellow wire, one yellow w/ black stripe, and one black. The lone plus is just one black wire. I dont get any juice to my ign switch-im wondering if this has anything to do with it?-doubt it. Either way- would like to get a new replacement. It is in the same wiring as the ignition unit and ballast.