I read this forum all the time [I recently bought a 1986 740 gle]. Thanks to all the people who take the time to post and share their knowledge. Does anyone know how similar the wiring harness is b/n a 1986 740 and 1985 740 [both non turbo]. It would seem that they wouldn't be that different and could be interchanged, but then they do have different part numbers so maybe not? Thanks.

The local guru for Wiring Harness questions is Dave Barton and his website is here:
http://www.linkline.com/personal/dbarton/WireHarnesses.html

I also would assume that the harnesses are very similar and it probably wouldn't be too difficult to do (if not downright easy). If I were in your shoes, I'd either contact dave or pick up a copy of the '86 and the '85 Volvo wiring diagram books and check the pins/colors/wires to see what wires are the same and what wires might be different. It might be something as trivial as the presence of extra wires for the old style voltage regulator that used a temp sensor under the battery.

I'm also in the same situation you are in. I've got an '88 740 harness that I need to install in a friends '87 740. I've picked up the '88 wiring diagram book and now I'm trying to find the '87 book. I haven't yet got around to inquiring of Dave, but it's on my list of things to do.

God bless,
Fitz Fitzgerald.
--
'87 Blue 240 Wagon, 252k miles.
'88 Black 780, PRV-6, 146k miles.

thanks fitz, I appreciate the info!