I hooked up my oil pressure guage, it only has three things to hook up(SENDER<POs<NEG), sounds easy enough right?...Nope......I have the sender unit hooked up properly (electrical not mechanical) and the negative and positive hooked up. No matter what as soon as either the negative and positive wires are hooked up to the guage the needle get burried emediately, this happens whether the sender unit is hooked or not..has anyone seen this before its driving me crazy??..I also tried hooking it up to the battery neg and positive too and the same thing happens...also it's not the guage because it has been send back and tested my the manifacturer and they said its fine...I am at a dead end..please help none of this makes sense to me?

 

My only guess is that the sender was not hooked up properly