940 Brake lights dead, fixed good, no warning lamp.

This is on a 1994 940. Any ideas?

Edit: I haven’t had a chance to look. Where is the brake light switch on these things?

Mods: the title is supposed to say “fuse good” not “fixed good”. Help please!

Just because the fuse is good doesn't mean it's making good contact.

If it isn't the fuse contact it has to be the switch or the bulb failure sensor.

FYI, the switch is on the pedal bracket under the dash.

I just pulled the brake light switch out from under the dash. It is showing continuity when pressed. Is that normal? It doesn't make much sense to me. Why is there a vaccuum line running to the brake light switch?

If the bulb failure sensor was malfunctioning, wouldn't the turn signals stop working too? Is the sensor one of the not-a-relay boxes plugged into the relay panel?

Thanks for your help so far hiperfauto!

The brake light switch is normally open so it passes current when the button is released. It should not pass current when depressed so it sounds like it's bad but that would make the brakes lights stay on all the time.

The vacuum line is for cruise control. If its part of the same switch, it's not the brake switch. It looks like this.



The sensor monitors several light circuits and can go bad on only one. It's the large round plastic can in the relay panel.

See Dave Bartons page for more info on the sensor and how to bypass it.

http://www.240turbo.com/volvo240mods.html#bulbfailsens1

It was the sensor. I did the “turn your sensor into a bypass module” thing as described on the linked site, and now all is well! Well, except I burned my thumb on some hot solder, but that’s pretty much normal for me.

Thank you so much for your help!