I don't know whether the Bentley shop manual has what you need, or if there is info in the 700/900 FAQ's. (BTW the 200 has a lot like the 700 & 900, so always look in there)


To replace the main wiring harness it makes a huge difference if the intake manifold is unbolted from the head and moved away from it a couple inches. A new gasket is required.

However, there are other possibilities. Not all the wires in the main harness go to dust (as in ashes to ashes, dust to.....) Look on the firewall in the engine bay about half way across, and find a gray connector with only four wires coming out of it even though the connector could hold eight.

Those are the wires that go bad in the main harness. They can be by-passed.

The wires that wrap the bottom front of the engine go bad, too. That's due to their location, there in the heat, oil, road crud, vibration, old age, etc.
That one can be re-worked, too.

Check this site for wiring harnesses. http://www.linkline.com/personal/dbarton/ They are not cheap, but are less than a dealer price. Be happy, when I got a quote on said harness on my 1983 245GL the part was $600 clams OUCH.

You will be well-served to own the Volvo Service Manual Wiriing diagrams for your brick. Go to http://www.volvotechinfo.com/index.asp and check if they are available. Buy one, there's stuff in there that Bentley and Haynes don't have.

Good Luck,

Bob

:>)