Does anyone know if the cab wiring harness for the 240z is universal between 1970 and 1973? any help would be great.

I'm not certain which part of the harness you are referring to when you say 'cab'.

There are three major parts to the 240Z harness - the engine compartment, the dash, and the body (or rear) harness. None of these sections are unchanged from year to year, in the earlier production the changes came only months apart.

I documented all of my prior research on this here:

http://www.classiczcars.com/forums/showthread.php?t=19793

Depending on what part of the harness yes their are changes check the sight Aren posted

Its the body harness, the one that goes back to the tail lights. Thanks

The reason I'm asking is cause I had body work done a few months back and the guy cut through 3-4 wires and did a make shift fix (didn't work) my datsun is a 72 and the wiring harness is from a 73.

From what I can recall since I had a 73 harness it had left and right speaker wires. Now my 71 might not have that it is the only difference I can think of. If you plan to put 73 wires in the 70 I think your good if you put 70 wires in the 73 you might need wires for the right speaker.

The reason I'm asking is cause I had body work done a few months back and the guy cut through 3-4 wires and did a make shift fix (didn't work) my datsun is a 72 and the wiring harness is from a 73.

I know a 72 and 73 are the same mine in the 72 had bare wires and was safer to replace the back section.