Any tips on adapting trailer lighting to my 850 should i need to tow a little u-haul? The 850 has a clutch - which is not optimal for any towing. I am guessing I'd have to splice into wires, nothing particularly built in. I did see some wiring on the ipd web site, but not for such a vintage Volvo.

Don't worry about the clutch. Volvo clutches are very robust. The most important thing is to avoid slipping it excessively while backing up, particularly if you need to go uphill.

I say yes! I recently put one on my 2000 V70 and find it very useful. You will need a powered taillight converter. On mine, I ended up having to pull the rear bumper to access the insides of the frame rails to install the bolts for the Hidden Hitch trailer hitch I picked up. The wiring is relatively easy to access-- I used solder and heat shrink to make the connections as robust as possible. I ran power from the battery through the accessory wiring tube under the ABS unit into the passenger compartment using 12 GA wire and a fuse holder.

I found wiring information on Matthew's Volvo site.

Good luck!

The only 'hard' part is running a wire from the battery to the left rear fender well. You do need a control box, as the brake lights and turn signals lights are on separate power lines, unlike most trailers with one light for both functions.

On my 855, the wire is exposed under the car and held to the brake lines with zip ties.

Don't worry about the trailer plug connector, you can let it out at the tailgate/trunk while you are towing and stash it back in the wheel well when not using it.
--
Keeping it running is better than buying new