Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 928 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Nov 2012
Posts: 4
Brake light switch

Where is the brake light switch on a 1979 porsche 928? What does it look like? The brake lights won't turn on, even with new bulbs. Can you provide a picture or a walkthrough video perhaps? I've googled everywhere for a picture/solution but they were all mixed/different answers so I am not certain of what to do. Thanks.

Old 11-23-2012, 06:57 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
Join Date: Oct 2005
Location: Owasso, OK
Posts: 386
Garage
The early 928's had two switches on the inboard side of the brake master cylinder. There are three electrical connections on each switch. One switch senses pressure on the rear brakes and one for the front. I would make sure the connectors are in place. If the brake lights still don't work replace both switches.
__________________
Dennis
Old 11-24-2012, 06:35 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Nov 2012
Posts: 4
Ok, I am not sure if I've found the right connectors or switches, whatever concerns you the most. The connectors were indeed in place but when I unplugged them out to take a close look at them. The back of connectors has green corrosion, perhaps it's the cause? Can corrosion be cleaned or fixed in any ways? If not, should I replace them first or replace both connectors and switches? If so, is there a manual on how to do this?

I've attached pictures so you may understand what I was talking about.







On a side note...the brake master cylinder seems to be in bad shape, don't you think? Should I do something or leave as it is?

Thank you.
Old 11-26-2012, 01:53 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Oct 2005
Location: Owasso, OK
Posts: 386
Garage
The corrosion could very well be the cause of no brake lights. If you braking is OK the master cylinder probably just needs cleaned up and painted.
__________________
Dennis
Old 11-26-2012, 05:26 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Nov 2012
Posts: 4
Hello, sorry for the long delayed response, it has been raining here plus a few storms, and my garage is full of my mom's crappy stuff so I couldn't work on my car there. In past week the weather finally cleared up which gave me the chance to work on the problem. I got the master cylinder out and I removed the two switches to inspect, they looked okay to me *shrugs* I went to Autozone and bought two new switches, replaced the old ones, then I put the master cylinder back in the place. The result is somewhat successful...Only rear left brake light works. Rear right one still remains light less. Perhaps some fuse or electrical wires blew/shorted out or something along that line? Any ideas or suggestions appreciated. Thank you.
Old 12-10-2012, 10:13 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Oct 2005
Location: Owasso, OK
Posts: 386
Garage
If either switch detects pressure you should get power to both brake light circuits. Since one light is working, the new switches are functioning. I would check the fuse, bulb, bulb connections and ground for corrosion.
__________________
Dennis
Old 12-11-2012, 10:20 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: Nov 2012
Posts: 4
"I would check the fuse, bulb, bulb connections and ground for corrosion."

Can you clear that up a bit?

Do you mean this:
Fuse box (or panel?)
Bulb lights
Bulb connections

Or

Fuse connections
Bulb lights
Bulb connections?


And what do you mean by "ground"? Where can I find those connections? In the fuse box near front passenger seat, I assume?
Old 12-11-2012, 01:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Oct 2005
Location: Owasso, OK
Posts: 386
Garage
All of the above. LOL

Actually each bulb has its own fuse, so I would check the fuse to make sure it is not burn out and no corrosion at the contacts on each end.

To check the bulb and connections remove the lens, twist out the bulb then make sure the contacts are clean.

The ground wire will come off the light housing and connect to the chassis. Make sure it is making a good clean contact.
__________________
Dennis
Old 12-11-2012, 02:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Petie3rd
 
Mrmerlin's Avatar
 
Join Date: Jul 2000
Location: Philly PA
Posts: 4,507
Send a message via Yahoo to Mrmerlin
Mr Bond i would strongly suggest to replace the master cylinder,
get new switches from one of our vendors,
Use ATE super blue racing fluid.
For the bulbs remove the light covers and clean the bulbs,
make sure they are both the same brand and wattage,
hint install new bulbs for each circuit,
check the fuses
__________________
^^^ Stan ^^^ 2011 BMW K1300S Magma red
1988 S4 Auto , Elfenbein Perlglanz, Pearl Gray
1988 S4 5 sp, Black / Black leather/ Carmel carpet
Old 12-11-2012, 05:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
1982 928 us
 
Join Date: Mar 2008
Location: NH
Posts: 802
Garage
tried cleaning? the black box up behind the ce panel. also in search here - lamp control unit? when youve pulled it away from its bracket be careful one disconnecting the harness but especially when unsnapping the lid all the wires will pop out, bad,lol. clean them , though box is known to fail and maybe have to slide open to circuit board and inspect/repair.

ground ball each side under quarter panels in the corners at hatch, (lot of interiors removal to get quarter panels out) cheat/maybe wedge a tool in there to hold it open- clean the grd ball of wires. cheat cheat,lol bend/crack the fiberglass/ theres foam backed leather(dont wreck the leather) itll smooth back, reglass the crack and while there if glue not holding leather fix leather edges... screw it back down .

it will be a nightmare if you took lens off looked at sockets/cleaned , replaced, ....

and the wire connections to each light contact any unhooked, the only way to get the housing unbolted from top bottom brackets to get to putting/cleaning those contact/wires back on is remove the bumper to do them. cheat/maybe lens removed looking at the housing with screwdriver you can see where the plastic connects, sliding/cutting them away (sawzall...) fix your lights and screw gun down the housing inside there at a place near bracket where it will hold wont damage wiring/housing/paint/gasket... and the lens will screw back on gasket/flush...

bumper comes off many extension reaches ?mm 6? bolts

the license plate light corroded? fix it too.

__________________
1982 Porsche 928 us
Old 12-15-2012, 03:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 02:44 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.