Saw two simultaneous and previously unencountered things occur today
on my '89 Toyota Cressida.
First I noticed that my cruise control doesn't work though the green
"cruise" indicator is going on. Second, discovered that my brake
lights are staying on, with all lights turned off and the vehicle off.
Right now I've got the battery disconnected.
What will cause either/both of these? Obviously I can't keep
disconnecting my battery every time I park the car and I need my brake
lights to work.
Thanks for all input.
It is easy to check for continuity on the brake light switch with an ohm
meter. The switch should be open when the pedal is not depressed and closed
with the pedal is depressed. Before you remove the old switch, check the
adjustment so that you can get the replacement switch close before you
install it and then fine tune it after it is in place. Also make sure that
the brake pedal is retracting fully.
If the switch is good, check for a short to ground somewhere in the circuit,
starting in the trunk.
Why do you think that? It depends on the method used to activate the brake
lights and crusie control. I agree that for the common brake light circuits
I have seen, shorting the positive 12V feed to the lights should blow a
fuse. But blowing this fuse muight also cause the cruise control not to work
depending on how things are set up. Also, I can imagine a system where the
brake lights are turned on by the car's computer. Such a system might use
the brake light switch as a signaling device that signals the computer that
the brake pedal is engaged by connecting a signal line to gorund. In such a
system, if the signal line was shorted, the brake lines might turn on
without blowing a fuse.
Probably you are right about a shorted wire in the trunk blowing a fuse, but
I am not sure that would also enable the cruise control. And given some of
the light monitoring systems used in some cars, I am not sure what a short
might actually do.
On 7/28/10 9:58 AM, in article i2pgfu$skd$ firstname.lastname@example.org, "C.
This being an '89, the odds that the switch itself has shed a crunchy
plastic part has got to be approaching 100 percent. Its not going to be
necessary to ohm out anything or test the switch for continuity, one look at
it will tell the story.
I was thnking of a very simple wiring system where the Cruise would see the
brake light voltage go high because the brakes were applied, and this would
shut the system down. Assuming a short, then the voltage would never go
high, and that would keep the system enabled.
Having said that, if the wire that turns the brake lights on were to short,
the lights would not come on and the fuse should blow. What happens to the
Cruise is beyond me, I've not really given it all that much thought. Since
the symptom set is that the Brake Lights are on and the Cruise is disabled,
then the thing I would be looking for is a stuck brake light switch. I'd not
be expecting a short anywhere in the system.
might not even be the switch but the pedal lever tab that activates it.
on hondas, it's a little plastic tab that pushes through a hole. if
the tab breaks apart, the switch pin pokes through the hole where the
tab would be and fails to switch off the lights and switch on the
cruise. costs about $2 new, or free at a junkyard [too small and they
won't charge you for it].
The line to the brake lights is telling the cruise control system to shut
down, as if you had pressed the brake.
I'd first check the brake light switch... is it stuck? Is it broken?
Is it properly adjusted? It should be mounted on the brake pedal assembly
somewhere. If that tests okay with a meter and isn't obviously bad,
start checking wiring.
"C'est un Nagra. C'est suisse, et tres, tres precis."
I'd start my search at the brake light switch mounted to the brake pedal.
This switch causes the brake lights to come on, and it disables the Cruise
My guess is that the switch is stuck in the position as if you were applying
As it turns out, I tried taping the plunger down and the lights go
off. When I look closely at the contact area on the pedal shaft,
there's a hole that's *just* big enough for the plunger to fit
through, so apparently something - I assume this tab you refer to
snaps into that hole and broke off. Will probably jury-rig something
until I can get the right piece.
yup, that's it. if you look in the footwell, you'll probably find bits
of the old one so you'll have a better idea of what it looks like. new
ones are relatively cheap. or they're free from a junkyard.
although they're known to fail sometimes in very old vehicles, in
principle the plastic tab/plug thingie is a good idea - it offers a low
friction surface which preserves the switch [there's a slight sliding
motion because the pedal swings through an arc], and it provides a
bump-stop for pedal rebound. one of those useless/useful things to have
in the spares box.
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