1994 940 Wagon

My wife uses this car to commute to work. One day someone pointed out that
her brake lights were not on. I checked the fuse (No.4) and it was okay.
Later a Volvo mechanic told me to check the fuse at its top, where a probe
can make contact. Both sides were hot. I had already checked the bulb at the
upper brake light and it was okay. I managed to get the switch out and
checked the wire into the switch and found no power. I had already checked
the switch and it was okay. The two wires into the switch are white and
orange but there is no indication on the schematic in the Chilton manual as
to what color wires go where. I have no idea where to check next. I would
appreciate very much any advice offered. Thanks in advance.
Derek in Florida

 

Perhaps you have found the wrong switch as the wires to/from the stoplight
switch (mounted and operated by brake pedal) are shown as Green/Yellow (from
fuse 4) and Yellow/Brown (to Bulb Failure sensor [relay]) and then on
Yellow/Red to left hand brake light, Yellow to right hand brake light and
Yellow/Black to high level brake light. These colours are the same for all
markets 1994 944 & 945. This information comes from the 1994 940 Green book,
Wiring Diagrams.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

Thank you, Peter, for your information regarding the wire colors. The
switch I took out (held in its holder with a clip) had a vacuum line
attached to it that I was told was activated by the brake pedal to turn off
the cruise control. The switch closed/opened the circuit of the two thin
wires, one orange and the other white plugged into the side of the switch. I
think now that they are not live until the cruise control is turned on. I
am just guessing. They in turn were connected to a large package of wires
and maybe in there I will find the wires you speak of. I will go back to
work on this tomorrow. I should probably get my hands on a proper schematic
of the system.

Regards, Derek