Fuel Pump wires?

[canada karl]

So I removed the fuel pump as the wire contacts were rusted and installed a fuel pump from the parts car. There are two black wires covered in a black sheath to connect to the pump. Does it matter which wire goes where? ie run the pump backwards?

[528i-1981]

The wires are likely just dirty and not black. The positive terminal on the pump has an M4 nut and takes the green/violet wire (at least on my 1981 car). The ground wire is the usual brown and has an M5 nut. Connecting them backwards will result in the pump running in reverse, but the different size nuts make it hard to get wrong.

[canada karl]

On this 530i I scraped back the black but the wires are actually black and the terminal nuts are the same. Might be an aftermarket pump and someone has redone the wiring at some point. I'm going to get a jar and a length of fuel hose.... 50/50 chance to get it right.

[Mike W.]

With the ignition off, ohm them out. Ground should go to ground and show continuity. Hot might feedback thru something, but not show near zero resistance.

[canada karl]

Thanks for the info Mike. I have the fuel pump working and I can hear the click when the AFM door is opened. My main problem now for the no start is no spark to the plugs when cranking but there is spark at the points. I sent you a PM about this problem of been trying to track down for days.Don' know if you have seen it yet. Lately I discovered I had the the two relays that plug into the combo switched around so I checked the parts car set up and got that fixed. The Combo relay on that car is the black plastic type but that should be OK seeing as how it's going from a 76 530i to one of the same year. Engine just cranked but nostart again. It has me baffled. I'm hoping to hear from you when you've had a look at my PM. Your help is always greatly appreciated.
PS I just bought new points as I seem to have fried the old ones when I hooked up the coil wrong! I haven't tried starting the car yet though. I was not able to get a new condensor locally so I guess I may have to order one on line and wait till it gets here before I proceed. I have a feeling something else is going on but I cant figure out what.
Karl