So I found the flexible circuit board was coroded and scared up and replaced it and a new rubber gasket. It worked till the rains started and the light bulb warning light on the dash came on. I went back and found the conector on the Rt rear light assy was dripping with water. I sealed the red to amber and white lenses with a thin coat of silicone sealent and drilled little weep holes in each compartment(at the bottom). Again it was wet when it rained, where could the water come in from. Then I had it with the origional parts and ordered a new rt taillight assy from FCP Groten ($95) and installed it with a light coat or silicone sealent on BOTH sides of the gasket. I noticed when it rains the water runs down the trunk and pours onto the top on the taillight assy. The new assy and sealant worked for the water but the Dash light bulb light kept coming on intermittantly. I started looking into the fuse panel when the light was on and the right rear was not working (with the new parts) and found the Rt taillight is on its own fuse. Come to find out the fuse wasn't making contact on the front side of the brass fuse holder (note to self, don't overlook the obvious). I found staining like water had at some point (in the last 20 years) leaked onto the brass and coroded it. I removed ALL the fuses and wire brushed with a brush the size of a toothbrush until the brass looked like new. I also lightly cleaned the ends of all fuses and put a dab of dieelectric grease on all the brass contacts where the fuses rest. I also made a duct tape bonnet or hood for the top taping it to the painted surface and out over the top of the fuse panel. Wile I never found this wet it appeared at some time water got in. Now my light problems are gone.

 

the water leaks in the top of old tail lights on the 240 sedans from the water channels around hte trunk lid. its kind of a poor design, but all the rain from the rain gutters tends to drain down the sides of the trunk gasket and onto the tops of the tail lights.

when they start filling up with water, I'll drill those drain holes which helps for a while, but in another year or two, its time for new tail lights. new lights should last 6-10 years (remember, these cars are 20+ years old already), and they aren't *that* expensive. plus new lights really spiffs up the cars appearance.

 

My 1st post. Thank you guys for turning me towards what my problem probably is. I Have a 1992 240 when i turn on the parking lights some times the dash light will go on. It will also go on always when i hit the brakes. All lights work with correct wattage bulbs.
What do you think please. I Thank You

 

when you say, the dash light will go on, do you mean the bulb failure yellow light?

those are a pain in the butt. if there's any even slightly corroded connections anywhere in the system, or if the two bulbs in a given pair aren't matched, that stupid bulb failure detector trips off.

it detects difference in current between the left and right bulbs of each circuit, and it doesn't take much difference to set it off. if I have to replace one bulb, I try and get two matching ones and replace the other at the same time. that helps. check for any corrosion on the light sockets, the flexible circuit board, and the connectors to the harness, clean the contacts, and use an electrical grease..

sometimes I think the ultimate fix is to replace the bulb failure detector 'beercan' with a bunch of jumpers that bypass it. that or just remove the bulb-out bulb from your dash.