Hey guys recently bought a new volvo 740 sedan 1990 b230ft with m46 for 1500 cad with 175k miles on it, pretty good deal heh.

So... I'm a noob when it comes to cars and would like to become a better mechanic and i'm running into a few issues mainly off in regards to the wiring for the battery im trying to replace...

Anyone know where i can find the battery wiring for the positive terminal have a 1990 volvo 740 or anyone have one for sale. So confused as to why there are 4 wires?
Link for better idea of what im talking about in regards to wiring and they are all sold out/NLA too...
http://www.volvopartswebstore.com/showassembly.aspx…
Any help would be much appreciated

Here is a pic of what i'm talking about the wiring needs to be replaced but i can't find the same thing available for sale anywhere do i have to modify it some how or is there another way around this what must i do first i want to get this thing running so badly :l

 

the big fat wire goes to the starter motor. the two medium gauge wires likely go to the 'positive terminal', which on a 740 is behind the dashboard on the inside of the firewall, above the pedals, the ignition key and many other things come off this 'positive terminal' (its a flat rectangular black box with a bunch of red wires hanging out the bottom). the 4th wire probably goes to either the headlight high/low relay, or the 'radio suppression relay', but I'm just guessing, I don't have wiring diagrams for 740's before 1991.