1995-850
I am making this a new thread in case I get some 'new views'. Bottom line: Key out of the ignition, step on brake, headlights and dashlights go ON! Took out the dash to see if I could 'see' anything weird (burned wires, crimped wires)...NOTHING. I can bring the car to the local shop on Monday, but I would love to fix this myself. It's just that I don't know where to start. Considering I know nothing about electricity...what do you all suggest? I am kinda scared to hook up the battery. Each time I do and step on the brake, I fear that wires are frying somewhere. Does the fact that the lights and dash lights go on when the brake is applied mean anything? A particular 'system' that I can explore? Relay? etc.? Sorry about the repetition, but I want to drive my car.

I could very well be wrong, but I believe the lights on when you press brake is a ground issue. I'm thinking your pedal pressing pushes some wire that is now exposed over to the light circuit.

Here's what I'd do:
Hopefully you have a multimeter, if not you can probably just get by with a multimeter..

I'd first hook up the Ohmmeter to the battery positive and negative terminals without pressing the pedal. It should read infinity or OL or whatever that means there's not a complete circuit . Then press down the brake pedal, You should get a reading, if I had to guess it would be somewhere around 100-200 Ohms, though could easily be more.

Assuming this plays out as I've described you get to have a little fun pulling fuses and taking readings when you press the pedal. I'd start with fuses related to cabin items radio/fan and move outward from there. I'd probably try them all just because i'm not doing it twice...

Eventually you should have a fuse (or two) that when pulled make the car read the same with both pedal pressed and depressed.

From there you've narrowed the circuit down to whats causing the short. Hopefully its one of the easy ones with only a few wires to trace. IIRC you did the dash removal so you should be able to confine yourself to wires in the dash/firewall area.



If you end up trying this and you get stuck/something different from what I'm guessing will happen/ whatever post and I'll try to help.


Parting questions: Are there any wires that are touched with the mechanical action of you pressing the brake?

Is the only thing acting up now that when you press the brake the lights go on? IIRC the brake lights would illuminate but since the key is off they should be off. That might mean that that circuit is suspect. Perhaps something just got caught?

And finally, when you had the keys in and you pushed the brake were the same lights going on?

A long time ago I had door chimes and indoor foot lights going on and off.
Found a one inch thick bundle of wires down under drivers side dash. Some of the insulation protecting the bundle hand worn away and then the individual wire sleeves were now worn away and making contact with a piece of steel down under. Who knows, there were a heck of alot wires in that bundle.

I see your point, but here's my concern with the 'fact finding mission': When I did push on the pedal repeatedly, there is a ground wire going to the steering column (black wire that is screwed to the column) that got hot (temp), and the insulation melted on some of it. So, I replaced that wire. I am concerned that too much activation of the problem will cause wires to fry...ones that I can't find (if not already fried)! If only there is another way to find the cause.

A ground wire heating up is an indication that there is a problem with your chassis ground system. Clean the main grounding points on the engine to chassis, and battery to chassis and see if that doesn't help. There should be a place where most of the grounds are brought together near the battery (I'm not familiar with the 850 grounding points) and it is probably corroded.

Regards,

OK...did as you suggested. With the battery terminals disconnected, I hooked up my meter. When the pedal was NOT depressed, the reading was different than when depressed. I pulled every fuse. The one that made a difference was the STOP LIGHT fuse...pulled that and no change in meter reading... the system was not being effected by the stepping on the brake pedal...all seemed well. The car started. That was all fine and good...then I hooked everything back up...fuse IN... The problem "went away"... WITH the fuse IN (the bad senerio), everything was fine...Now I am back to square One. I now have to wait for the problem to resurface. For some reason, horsing around with the fuses, etc., seems to have joggled 'fixed' it. Damn....

Horsing around with the cables will fix it because it seems like you have a ground that isn't quite in contact that moving around makes the circuit complete. Whats nice is that your problem's gone until it gets re-jostled into trouble.. You have checked all your ground points in the dash right? You blew the one in your steering column and replaced that, how about the others? There's one by the drivers door, close to window height, there's one near the blower motor, and you might at well check the one by the parking brake. I'm hoping one of these is loose, but...



Now as to the Brake Light, I believe that's the only thing on that circuit for your car (fuse 12 if i'm not mistaken) so you should only really have to check those wires for any break in the insulation. The switch is actually on your pedal and there's 4 wires coming and going from it. Before you do anything more you should probably disconnect your battery, this circuits hot at all times... Anyway, My guess is going to be the Yellow wire coming off the switch, because when you press the pedal this gets current too. That wire's going to run all the way back to your trunk but there's no need to trace it beyond the front seat.. To inspect its probably easiest to run your fingers over that wire and feel for brakes, as well as a few inches either side of every wire that comes in close contact with it. You also have the red wire (this one's hot regardless of if you press the pedal or not, so be extra careful unless you've pulled fuse/battery) and do the same. The other two wires are for your Shift lock, they're green and blue/yellow and luckily are on a different fuse (28 i'm pretty sure) that didn't make a difference when you pulled it, so you don't have to check them...


One final check I'd like you to do, after you hook up battery but BEFORE you start the car, run a voltmeter across the terminals and make sure its constant voltage. If its dropping you've still got a short..

I'm not sure if this was directed to his or my response, but do the one I suggested with your battery disconnected, hook the ohmmeter to the wires that your battery would hook to... You'll still get readings different because the ohmmeter puts out a slight voltage/current but it isn't enough to fry a wire.