88 930 Brake Light Question

[tailwind22]

88 930 and brake lights quit working. I have checked the fuse panel and the bulbs themselves and no issues there. The brake light switches are located on the master cylinder and I verified that I have power going into the switch and no power coming out when the pedal is depressed. This means the switch is bad, correct? Or could it still mean that I have a ground issue somewhere? Trying to eliminate all options before ordering new switches. Thoughts?

[DohertyCM]

I have not had this problem...but if you can remove the switch...you can do an ohms check on it and see if it is bad or good. The way you described it, sounds like a bad switch. But test the switch by itself and see what you get.

[infraredcalvin]

I don't know if the switch is the same as mine, but on mine the switch is actuated with a little metal (and plyable) arm, to me it seems like a stupid design that just begs for fault. Sometimes it just needs a little adjustment, takes about five min at the pedal cluster with a philips head screwdriver and a bit of patience. Once you remove the floorboard and look at the little black box, under the brake pedal, with the silver arm sticking out you'll figure it out...

[JFairman]

Originally Posted by tailwind22

88 930 and brake lights quit working. I have checked the fuse panel and the bulbs themselves and no issues there. The brake light switches are located on the master cylinder and I verified that I have power going into the switch and no power coming out when the pedal is depressed. This means the switch is bad, correct? Or could it still mean that I have a ground issue somewhere? Trying to eliminate all options before ordering new switches. Thoughts?

An '87 has two brake light switches on the master cylinder. They are switched by hydraulic pressure as you press the brake pedal down. I don't know why they have two switches, I guess one is a backup to the other if one stops working.
I replaced them both because the brake lights wouldn't come on with light brake pedal pressure when slowing down easily around town.

I bought the replacements from a Porsche dealer because that was the lowest price on them I found.
They are not fun to replace... kind of hard to get at and stuff has to be moved out of the way from what I remember.
Then you have to bleed the brakes to get any possible air bubbles out of the master cylinder.

[tailwind22]

Originally Posted by JFairman

An '87 has two brake light switches on the master cylinder. They are switched by hydraulic pressure as you press the brake pedal down. I don't know why they have two switches, I guess one is a backup to the other if one stops working.
I replaced them both because the brake lights wouldn't come on with light brake pedal pressure when slowing down easily around town.

I bought the replacements from a Porsche dealer because that was the lowest price on them I found.
They are not fun to replace... kind of hard to get at and stuff has to be moved out of the way from what I remember.
Then you have to bleed the brakes to get any possible air bubbles out of the master cylinder.

Yes, the vent hoses are not going to be fun to remove as you state above but I do believe that the switches are the culprit. I will get them ordered.