My '92 965 has developed a peculiar problem...first thing in the morning...I start the car...all is fine...I drive about 10 blocks and the red brake light on the dash comes on...it stays on for about 5 blocks and then turns off...and that's it...it doesn't come on until the next morning...even after sitting in the parking lot at work all day
I drive the same way to work every day, it always turns on at the same spot and off at the same spot
The brakes seem fine, the fluid is fine...no squeaks or shudders or anything along those lines

Is it just a short? or should I be concerned?

Dear Buannan,

Good p.m. and may this find you well. This sounds as if there's a loose connection. A heat build-up resulting from a loose connection, might cause a transient short, that triggers the trouble light. When the current ceases to flow, the connection cools, and conductivity is restored. The warning light goes out.

Alternatively, there might be a bump on the route you drive. When you go over the bump, the impact shakes a weak connection, and so triggers the warning light. As you drive, connectivity is restored by the myriad small bumps, that are part of daily driving.

My suggestion: take a different route to work, and see if the light comes on and then goes out, after the same intervals. If there is no change, the malfunction likey is heat driven. If the light doesn't come on, the malfunction likely is "shock" driven. Taking a different route - whether smoother or bumpier - should change the malfunction pattern, if the malfunction is impact driven.

Finding the weak connection - which could be on the supply or the ground side of the circuit - will take the wiring diagram and a lot of patience.

Hope this helps.

Yours faithfully,

spook

thanks spook

you response went along with my thoughts on the subject, I just wanted to make sure I wasn't missing something major that would need to be taken care of right away

what a relief that it is most likely just a loose connection and/or short

nothing makes your heart beat a bit faster than seeing that red brake light go on while in rush hour traffic in seattle...lol

thanks again...I'll let you know once I hunt down the problem

Dear buannan,

Good p.m. Don't put any faith in my conclusions. I am by no means a brake - or anything else - expert. I hope some fellow brickboarders - who are bona fide experts - will weigh-in.

I believe that 940 brake systems are plumbed, such that there will always be some braking capacity, under all but the most adverse conditions. Nonetheless, until you've tracked this down, try to leave some extra room.

I know this is hard to do. There are many, who do not understand Physics, as it exists in this part of the Galaxy. Such persons thus try to do things which may be quite feasible in their home Galaxy, but which cannot be done here on Earth, i.e., two objects occupying the precise same space at the same micro-second.

Best of luck with your detective work!

Yours faithfully,

spook