Most 200 series Volvos have a tach wire as part of the original wire harness. It is white w/ a red stripe and is connected to the coil.

The big clock can be removed in 5 minutes abd replaced with a big tach...cost is $20 for the big tach from a salavage yard...

To remove the speedo unit, pop off the 2 square gauge cover plates on the right side of the speedo and remove the 2 phillips screws. Then go to the left soide of the speedo pull off the headlamp and dimmer knobs and pop off the coverplate and remove the 2 phillips screws. Pull the speedo unit out a bit and tilt it so the left is out farther than the right, this will allow you access to the back of the clock. Locate the 4 screws that hold the clock in place (use a stubby screwdriver-phillips), remove them and then locate the tach wire (white w/ a red stripe) and plug it into the single spade lug at the bottom of the tach. Slide the tach onto the 3 pins that the clock was mounted on, this provides lighting, power and ground signals to the clock/tach. Reinstall the 4 screws and slide the speedo back in place, replace the 4 phillips screws, the cover plates and knobs and that's it..

Internet Carparts has the tach or go to any salvage yard and pull one from a stick shift 240, it doesn't matter if it is a electronic speedo or a cable driven speedo (my tach is from an 83 and my 240 is a 90) but be sure it is from a 4 cyl not a 6 cyl.

Your '88 240 should be close enough to my '91 240 because I got my parts from an '88 240.

I went to the bone yard and found a wreck with a tach and a little clock over to the right where your car has a blank plate.

On the wreck, pull off the trim around the clock, (save), slide the clock straight out unplug the wires and follow them to the back of the tach and unplug them from the tach, save these wires, and save the three little rubber gizmos that held the clock still. On the back of the tach you will see one white with red stripe wire, thats the signal wire. Study where it comes from your car will have that same wire buried somewhere in the harness, mine was tough to find, but it was there.

The tach then unbolts with three little bolts, then pull it straight out.

There are several electrical contacts that are there so kind of walk it out.

I suggest pulling the bone yard one first. I think I was charged $5.

I also got an extra clock trim and rubber gizmos and put a oil pressure gauge below the clock, those holes behide the blank filler panels seem to fit all standard (3"?) gauges. In all the job was under an hour to install.

Steve M.