blinking oil light, and middle gauge

Hello, new to forum. Recently acquired a 1982 Karmen convertible Rabbit and am stumped. With engine off, turning the ignition on makes the oil light blink 6 times, then it goes out. Will do this repeatedly. When engine runs oil light is out. Driving car makes oil light blink. Haven't hooked pressure gauge to it yet. This is a gas engine, fuel injected.

Also, can someone tell me what middle gauge in cluster is for. My 84 Rabbit book[I also own a 84 Diesel Rabbit] indicates that it should be a clock, but this gauge [VDO] says BAR and whatever it is, it fluctuates with the tach.

Any help on these topics is appreciated........

its basically a pressure gauge, its the equivalent to a pressure gauge on a supercharger. the rabbit fuel injections were made for rally purposes, and then became "citizen" vehicles, so the rabbit basically has a built in "supercharger" and thats just a gauge for it...

The oil light is on a solid state circuit in the instrument cluster which makes it flash with engine off as described. If it comes on while driving there is a problem. Note this is a dynamic system that uses high & low pressure switchs (one on cylinder head & one on oil filter housing. One may have a problem, or it my be an internal fault of the electronics. I can't tell you how many times I've seen these cars with a "normal" circuit bypassing the electronics due to such failures. Basically you just wire a new light off the normally closed switch. The gauge on the '84 sounds like an oil pressure gauge, is it a GTI?