Thanks for all of the replies. It will take me some time to sort this out and I will report back. My 740 definitely has black/white wires in the headlight harness. I'll need to do some testing to see if they are what I think and will try to buy the manual because I need to be prepared for electrical issues. The Haynes manual is practically worthless. Oh, the sockets for the signals and parking lights were fun. I had to modify some found locally.

I hooked up the new lights to existing wires and relays and everything worked except the fogs. We'll see if the relay holds up.

The lights are fabulous and didn't even require aiming. They were used and had a couple of issues; one being a broken bolt that was impossible to get out. There will be no finding a piece of trim around here, so I will be modifying the old one. It's a driver, not a show car. We drove it to town (over 100 miles round trip) on Wed. Here in Montana we never see other Volvo's. As far as I know, there is one other 740 in the county and no other 240's It sits 90% of the time and we drive the old 240 locally. We now own 4 vehicles. The 740 has the least miles at 154K. All the rest are over 200K.
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Bob