I own an '89 240 gl wagon with a non operative cruise control. Recently I realized all of my brake lights were not working. I changed the harness that activates the third brake light when I first purchased the car and everything worked fine. I was told by a friend to check the little switch that the brake pedal depresses to activate the lights and activates the cruise control function. A continuity test shows that the switch is not faulty, although the air hose for the cruise control is old and cracked . The fuse in slot #6 is fine. I don't know where else to look. Any hints?

Just to expand on Randy's tip—the cruise system senses ground via the "bulb side" of the brake pedal switch--to and thru the bulb sensor--to the brake light bulbs--and thru their filaments to ground.

In normal operation, that point goes to +12 when you hit the brakes, which drops the cruise out. But if cruise and brake lights are both inop, the path thru the BFS is the likely suspect.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

The symptoms you describe many times are traced to a broken solder joint in the bulb out sensor. It is a big red round relay assembly and I believe you will find it up behind the instrument cluster.

Remove the cover and examine thejoints on the components at the top of the relay and resolder the broken one or all of them if you can't see which one is obvious. New replacement aftermarket relays are about $100 so re$oldering $ave$.

Randy