1997 E36 328i - Interior main light comes on when I put the brakes on !

[Franky goes]

The harder I press on the brake pedal, the more intensity (Voltage) goes into the main interior light located just above the rear view mirror.
It's actually cute and I'm not sure I would fix it if I was sure there is no shorts anywhere in the system.

From experience I think this is the classic loom of electric wires going to the rear hood that is dammaged at the location were it bends.
I checked and everything seem to be fine.

Any suggestion, past experience with same or comments will be much appreciated.

Thanks

[woody328is]

Cute may burn your car down if it's a genuine wiring short to ground, or through another circuit via a chaffed wire. I would start with a visual inspection under the dash and around the brake light switch area. Don't sleep on this or you may be sorry.

[boarder2k7]

The fact that it varies with pressure points more towards an under dash fault than a trunk fault. Definitely look under the dash carefully as woody recommended.

(This also sounds like a great prank to wire up intentionally....)

[JDStrickland]

It is nonsensical that the light changes intensity as you press the pedal more aggressively. The light is binary, on or off. The brake pedal switch is binary, on or off.

Having said that, I'm not sure you actually want to be driving this car. I think a diagnostic strategy would be to unplug the tail lamps and see if the interior lights still come on with the brake pedal.

[boarder2k7]

It's only nonsensical assuming it's connected to the switch. If it's a short it could do this due to the connection improving as its pushed on more. Improper connections (shorts) will often exhibit this type of behavior.

[woody328is]

boarder and JD are both right but if the pressure of the brake pedal, not the switch action is causing the short then something under the dash area related to the light could intensify as small movements are made causing a wiring harness to shift position.

- - - Updated - - -

My point is the harder the pedal is pushed the more things move around causing a better short circuit connection or ground feedback through a circuit.

[MisterM52]

Could be a case of Demonic Possession?

I would start looking at the door latch switch (that if hold for few seconds) flashes the interior lights, then you could pop that light assembly out and see if any wires are shorting, could be a range of things and you rather get your hands dirty and fix it.

but again; If all else fails, call a priest.

[Franky goes]

Update
I just unplugged everything that was acting up knowing full well this is not solving anything.
I plan to try the suggestions above and will report.
Thanks for taking the time to suggest solutions.

[spyderg0d]

I bet its safe to say its not a mod. It would be illegal here in ny. Bright interior lighting at night while driving is considered a saftey distraction.

I wonder if some one was special enough to wire a potentiometer to the brake pedel switch.. Smh. Ive seen more dumb things on teeneager owned vehicles,

[Franky goes]

It upsets me to no end when someone asks for help and does not report the results so people who are facing the same issue get to the bottom of the thread and are no further ahead. That person very often being me... So I make it a point to get back even if it has been a long time like this one...

I came to the conclusion that the door switch was worn and failing to engage as suggested by MisterM52. You could see the wear on the plastic where it contacts the D-ring holding the door closed. I replaced the driver side in the front because it was showing wear and is the door that sees the most action.
Well... Epic fail. It was still behaving the same. I gave up and got used to not having interior lights.
Last month a bulb (!) went off in my head. Maybe the faulty switch is one of the other 3...
Well it was the rear driver side door that was worn past the design specs.

The test is simple and requires a bit of patience.
Turn the light on in automatic mode.
Close all the doors and lock them. The lights should turn off in a matter of seconds. If not, one of the switch is faulty.
Open one door and depress the contact switch behind the D ring on the frame around the door with your finger. Lock the car. If the lights turn off in a matter of seconds the switch you are depressing with your finger is the faulty one. Two much plastic is worn. Replace and enjoy interior lights again. Now that they are back, I would not wait 3 years to fix it.

Sorry for the long wait but it is fixed.
The reason it was sensitive to the application of the brakes is because braking makes the unibody twist ever so lightly that the switch moves just enough to make contact.

The twist (!) is that when this start you could trouble shout that way and not find the faulty switch depending on how the car is parked. If it is not giving you results, park the car diagonally in an incline to provoke the malfunction for the time of the test.

Thanks for the suggestions. Success.