Volvo Repair: 1990 volvo 240 wagon, volvo 240 wagon, volvo 240

Question
I would like to try to repair this wiring problem myself. Can you explain to me the process, on how to make this repair. Thank you.  
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Followup To
Question - Regis:
I have a 1990 240 wagon.  It appears that the wires that run through the hinges on the tailgate or back door are broken causing my rear defrost and back wiper not to work.  Is this analysis correct and how could I repair it.  Thank you.
Answer -
yes that would be correct there are replacement harnesses for the tailgate left and right side.they are not too expensive but are somewhat difficult to install.

Answer
it would be too difficult to explain the process.it would be better if there is a dealer near by you could try asking them for some descritption of the process.it will be easier in person to show someone some of the things you would need to do.if you still need to I would try to explain.