Gama

(89 928 S4) I have recently rebuilt a door switch which I was hoping was going to sort out my Interior Lights but alas no luck. Door lights switched down(come on when door opens?). Open doors and no lights coming on, though there is a click that comes from a black relay with the word "Fensterheber RDW" (Relay #6?) on it. Overhead and Hatch lights come on when either pushed forward or backward with hatch or doors opened or closed, there is no click from the relay. Does anyone have any clues as to where the fault might lie? Thanks in advance.

Mrmerlin

if you wiggle the pin switch do the lights come on? If not try removing the switch and touching the wire to ground, that is what the pin switches do.
If the lights come on then you need a new switch, I think they are soldered onto the wire , dont use too much heat as it will melt the center post

Alan

From what you say it sounds like your lights are all wired up wrongly - this is actually not uncommon... folks take them out then realize its not obvious how they go back together - All the lights are supposed to be connected the same so should work the same... that they don't incidates part of the problem...

Take out the door lights and check the connections...

The bulb direct connection end should go to a red wire - the switched end should have a Brown + a Brown/White wire - the order is not important - it just affects the direction of switching.

The roof is similar - the fixture frame should get the brown wire and the switched end the brown/white wire while the bulb direct connection end (nearest the frame connection) should get the red wire.

If these are swapped it creates many different issues.. if the roof lights have the brown & brown/White wires swapped they will behave as you note. The doors may behave as you note if the red wire is swapped to the switched end...

Its a simple circuit but confusing until you understand it.

Alan

JHowell37

I'll have to try this out. My interior lights have been baffling me for quite some time.

JHowell37

My problem is solved now. Thanks for posting that info about the lights.

Nicole

Another thing to check for is deformation of the clear plastic. I've had to replace two dome lights and an engine light because of this. Since I switched to the LEDs I don't have to worry about this anymore...

Gama

Ok so the door lights were incorrectly wired as you said Alan. All lights (in the "come on when door open" setting) now stay on with the doors and hatch closed. Which would leave me to believe one of the Door or Hatch switches is faulty? The relay is still clicking when I press the switches on the doors in and out. But when I do this with the hatch switch I dont hear any clicking from the relay. Could this be a clue to the hatch switch being the problem? Seems to look as if it is operating as it should.

Alan

The hatch switch drives the lights directly - not though the relay.

If the relay clicks when you open the door - its likely it works correctly.

The center roof light if swapped as I noted (Brown & Brown/White interchanged) will cause the lights to stay on in switched mode ragardless of the relay - so will any other short of the Brown/White wire to ground (any exposed metal on the car).

Red is +12v from the interior light fuse
Brown is ground (so is any exposed metal on the body)
Brown/White is grounded by the relay to make the lights come on in switched mode.

Alan

Jim bailey - 928 International

Also can be the relay it has a approx 30 second delay which keeps the lights on after you shut the door sometimes it forgets to count...

Alan

Actually - another thought is that the rear hatch switch may heve disintegrated and when this happens they commonly fail on rather than off. Take out the rear tool panel and look under the bottom of the hatch reciever - there is a brown/white wire with a quick disconnect connector to the switch - pull it off and see if your lights go out in switched mode. If so this switch has failed 'on' - you can order a replacement just for this part - meanwhile just disconnect it temporarily (wrap it in tape).

Jim for the relay to be always on the contact would have to be always closed (= coil current drain, or welded stuck) - either way it wouldn't click...

Alan

Jim Reay

When replacing the bulb (it had fallen or been knocked out) underneath the parcel tray at the the passengers feet, I appear to have blow a fuse. My interior lights can be switched on, but do not come on with the automatic setting, and the red hazard lights in the doors do not work. I have checked all the fuses, but they appear okay, and I cannot spot anything else not working. I would appreciate help.

Jim Reay

Sorry - Model is 1991 928S4

Alan

So Replace fuse 22 & 25 (don't just look at them.. either replace or test with a meter).

If you blew the light over the panel - that should be just fuse 22 and it should not have blown fuse 25...?

Anyway check/replace these first..

Alan

Jim Reay

Fuses tested, and main suspects (as above, plus 41) replaced. No joy. Might I have cooked the timing delay, although why this would go before the fuse would seem pretty bad luck. Should then something else not be working? How can I test, preferably simply and in the car?

Thanks, Jim.
1991 928 S4 (Japanese)

Alan

Jim you don't actually have a delay relay - on a 91 and newer it is integrated into the alarm system (as is central locking). Check Fuse 17 for the alarm unit feeder. Do your central locking and alarm features still work?

So the lights work in directly switched mode? When you open a door do you still hear the click of the relay as before?

I'd almost suggest you look at the light fixtures again and ensure they are wired exactly as I noted - its the only way everything will work... different miswiring could get you the results you note...

Alan