So a 90 240 DL followed me home last weekend and with the prospects of a couple of extra days (with the holiday weekend) and a young lad looking forward to driving the car, I am hopeing to get the main obsticals to it being on the road done this weekend.

The easy one (maybe - maybe not) is going though the brakes. The previous owner was metal on metal on both the front and the rear. I did the fronts last weekend - prestty rusty but not too bad. I have just started the rears and the WD40 is working on the pins that hold the pads in. The fronts were fairly frozen but the rears are apparently softer pins as they are starting to mushroom before moving (bottom ones). Hopefully the WD40 will do the job.

What I really need input on is the rear lights. I haven't looked at them yet but I have done a little searching of threads here. The ideas which I got from the threads are the connections on the fuse block (have not found it yet) and the bulb sockets and connectors. The PO claimed to have had the printed curcuits on the rear lights replaced and they do look fairly new so I am suspecting the problem is somewhere forward of the units themselves.

Any other ideas on where to look at getting the rear lights working relably would be appreciated.

 

I've heard a lot about the printed circuit. The quickest way to test them I would say is get a multimeter (very essential for trouble shooting old Volvo's), and an assistant to turn on the light you want to test. Connect the test leads to the contact points on the printed circuit and one to ground and look for 12 magical volts! Also check continuity of the grounds.

For busting rust I really like PB blaster. Shoot it the night before and it breaks it loose. I've had more luck with that than WD40.

Good luck!

 

even better than PB Blaster is AeroKroil. or a homebrew mixture of 50% Acetone, 50% red ATF. Wear gloves when you use this stuff.

these cars use the funky old ceramic fuses. I highly recommend just replacing ALL the old ones with the copper/brass kind, you can find these on ebay (sold as mercedes fuses)
Mercedes Ceramic Fuse Set NEW 8-16-25 AMP Set NEW FLOSSER | eBay
or whatever (I searched for 'mercedes fuses')

clear the spring contacts of the fuse block before replacing them.

if _all_ the tail lights are out, I'd suspect the ground connection in back.

on the 240 sedan, when the rear light assembly gets old, it develops hairline cracks, and rain that goes around the trunk gutter gets dumped on them, and leaks in and the lenses fill up with water, which overflows and swamps your trunk. best solution for this is to replace the whole lens fixtures. but drilling small (1/16"?) holes in the bottom corners of each lens cell can drain this water out and get you another year or so.