Are there any Chrysler electrical guys that understand why they did the things that they did back in the day? I'm talking about the engine harness on a 71 B&E body and how the oil pressure indicating circuit was wired. On the oil pressure sending unit, if you have a Ralley gauge set up there is what is called a resistance wire that goes from the sending unit to the regular wiring harness. The book shows this wire for both the Hemi and a 440 and my 383 RR had this wire new. When set on the 20 scale on a ohm meter it shows a little over 30 ohms. My question is, why was this wire there and everybody I talk to has never heard of it. Is it really required?

Didn't Chrysler add a low oil pressure light in addition to the gauge on the HP cars, possibly as an option? A resistance wire could effectively control a low pressure light until the switch reached the correct resistance level.

I suspect that because most performance oriented guys replaced the factory gauges with aftermarket gauges shortly after purchase, that extra light option probably was of little demand or of little use and was probably discontinued.

71 & 72 was a long time ago.