tjk34

2002 Honda Civic LX Sedan

Brake light switch has just been replaced
Shift lock solenoid has just been replaced
No fuses are blown

After performing the above-mentioned steps I am still having this problem.

I have a factory alarm and I can almost now predict when the problem will happen. I disarm the car and the horn sounds muffled. Sure enough, car is stuck in park and brake lights don't work. I have even had moments where I press the horn, while it is stuck in park, and the horn does not work at all.

ezone

Got a voltmeter?

ezone

Need to do this check WHILE the shift lock, brake lights, and horn do NOT work!


Jam a stick between the brake pedal and the seat so the brake lights stay on (no matter if they will come on or not).

Use a voltmeter to check fuse 7 in the underhood fusebox.
Check it using the bare metal tabs on top of the fuse, don't take the fuse out.

If it shows low voltage on both sides, then check fuse 5, 8, and 10 the same way. And see if the hazard lights work or not.

If it only shows low volts on one side of the fuse, replace the fuse.

If it shows full battery voltage on both sides.....see if the brake lights are now on full brightness and the horn works.

tjk34

Yes, I do

tjk34

Should I just replace fuse 7, 5, 8, and 10? Or is this test an indicator of possible wiring issues?

ezone

NO.
It's a diagnostic step.
Electricity isn't random, it's logical. Thus, the logical testing sequences.
A wiring diagram helps a lot too.

Fuse 7 runs the horn and brake lights.

Fuses 5 7 8 and 10 all get their power from one of the battery feeds. If all 4 fuses lost power, it would have to be something common to all 4, that's a likely poor battery cable connection in the fusebox (white cable T-1, passengers side of the box) or battery cable, or something.
That's why I said to check the hazard lights. They run on fuse 10. IF they quit at the same time as the brake lights and all, then it's gonna be something like this.

If only one of the four fuses lost power, it would not be because of that same cause above. It would have to be something else.
Test as described, see what's up.

ezone

See if wiggling the fuse brings your lights and horn back.

tjk34

Thank you, I will do as you instructed

ezone

Are you familiar with this method?




You could just replace the #7 fuse on the off chance it's a cracked element.

tjk34

[quote=ezone;4650573]Are you familiar with this method?


It appears I am to use the voltmeter to touch the tiny metal pieces at the top without removing the fuse, if I understood you correctly. I also wanted to mention that I removed every single fuse in the fuse box to check if anything was blown so I would think that would have wiggled something? (In response to your "wiggling the fuse" suggestion)

ezone

[quote=tjk34;4650575]That's it.
Wiggling the #7 fuse, to see if it has maybe a loose fitting terminal inside the box. Gotta be able to see the lights though, see if they come on as you wiggle it.




You could replace the #7 fuse just on the off chance it's a cracked element.

tjk34

Is there a specific range on the voltmeter that would identify it as a "low" reading?

ezone

Volts read at the fuses can only be as high as the battery voltage.
Those fuses are powered directly from the battery.
It SHOULD have battery voltage at the fuses.

If it's significantly less, it's a huge problem.


If there is no load on a circuit, it is easy to show full voltage across a poor connection. That's why I said to jam the brake lights on. That keeps a load on that circuit and should show a large voltage drop across the bad connection, if that's what it is (and if it is acting up at the time you check it).

tjk34

OK testing is complete. Car was experiencing shift lock jam and no brake lights at time of test. Horn was working at time of test.

Fuse 7 measured full voltage on both sides.
We got curious and checked others (I know, not logical) they are all measuring full voltage.
We turned on hazards and they did not work and they sounded horrible like they were struggling to make a clicking noise.
We jiggled fuse box and hazards came on, brake lights did not.
We removed fuse box to look for obvious wiring disconnects and could not see any
We removed bottom part of fuse box to reveal additional wiring and noticed a bunch of light brown gunk all over the wires, is this normal?
What now?

ezone

I know I said some crap about electricity is logical, but it doesn't always seem that way until AFTER the true problems are found.


Um, when was the last time they were ever used and actually known to work properly??

Houston, we have a problem.
Not positive exactly what yet, but you identified a likely bad connection.

Yes, it is dielectric grease. A sort of waterproofing they use on exposed terminals and wiring.



OK, so, possible fusebox or wiring issue for the hazard lights, and nothing new on the brake lights.

This isn't supporting the theory of the horn involvement. Yet.

So, how about checking for power at the brake light switch next?
White/green comes from fuse 7, so you should get battery voltage there
White/black sends battery voltage to the brake lights with a closed switch (pedal pressed).

If equipped, the other 2 wires on the brake switch are for cruise.

tjk34

Hmm... on the hazards, they are also inconsistent. The last time I tried to use them was when my transmission failed in June 2013 and they made the same noise then.

We will test the brake light switch wires next.

Thank you for helping us

tjk34

I hope we were doing this right...

No voltage is being read from the green/white wire nor the black/white wire

ezone

Ok so you had power at fuse 7, but no power at the brake switch.
There must be an "open" in the circuit between those two points tested.
Next steps would be to narrow the test points to locate the problem.

That leaves
the harness connections on the bottom of the fusebox in the engine compartment,
harness to the interior to the
junction block under the dash (fusebox)
and from that to the switch.



Bottom of the fusebox in the engine compartment, gray connector with 14 cavities (middle connector of 3 in a row), check the white/green wire in cavity #12 for battery power




Then the same color wire ends up going in to the dash fusebox.
Far left connector, second row from the top in this image

(ignore the arrow here)
Looks like this connector has 8 cavities.

Got 12v on the white/green wire here?



Next, it exits this box from a connector on the back, and goes to the brake light switch.

Best I could find in a GIS.

Um.... viewed from this angle, its in the middle connector, top row. Same wire colors as before.




I would have been reeeeeal tempted to just splice a jumper between the brake switch and a power circuit, hopefully still within the correct circuit. With proper fuse protection of course.

tjk34

delete this comment.... we had a bad ground we are starting the test again

tjk34

OK, here is what is happening:

Shift lock is jammed, horn not working, brake lights not working. Successful environment for our test. We remove the fuse box to test the wire and the minute we move the fuse box the horn works, brake lights come on, and shift lock releases. We tested this 3-4 times (putting fuse box back together and taking it apart again). Every time we snapped fuse box into place, car jams. When we remove fuse box to expose bottom wires, car acts normal. I am referring to fuse box by engine compartment

ezone

You have it narrowed down! LOL
Just gotta figure out WHAT though, box or wiring. Or a fuse contact? What is the smallest thing you can wiggle and make power come back on?
One single fuse itself??

What about the hazard lights, did they quit too?
ABS warning light ever on? (Fuses 8 and 10 feed power to the ABS system. #10 is a square 40 amp fuse.)

When it has all quit working: You should be able to check voltages on each of the fuses mentioned earlier (5,7,8,10). Are they all the same? Battery voltage or not?

Wiggle the 2 battery cables going into the front edge of the box.
Check tightness of the cable bolts and bolts for the fuses. Or screws, whichever.

tjk34

OK shift lock stuck, horn not working, brake lights not working, hazards not working:

With foot NOT on brake, all fuses (5, 7, 8) read full power (we don't know how to test Fuse 10 though) No ABS warning light on

With foot ON brake all of a sudden NO voltage readings on fuses 5,7, 8

I should mention we are curious at this jumper theory. My goal is to sell this thing and obviously cannot show it with it getting stuck in park

ezone

So they lost their power source.

Keep it so this problem is active.
The problem must be present and active in order to figure out where the power loss is at.



Do you have power at the terminal marked "BAT"?
Remember, the problem MUST be present during this check.
Wiggle that white wire, does all power come back?
Is the screw loose?

Is this cable losing its power at its source (positive battery cable clamp)?

CraigW

iTrader: (1)

ezone certainly has you pointed in the right direction, stay with it.

You could ge a 12 volt test light for a few dollars, the super sharp tip allows you to pierce the insulation of the wires easily. And you can set it in a circuit that is dead then watch the bulb as you wiggle wiring/connectors for flickering, or circuit voltage returning.

tjk34

I wanted to post an update. We jiggled the white cable back and forth and kept hearing a clicking sound. We tried to test the fuses with each click but were unable to get it to click again when we were ready. We then tested Fuse 7 again and it read 0.03. I thought.... wait a sec.... low reading = change fuse. We popped a new Fuse in there and the horn chirped nice and clear, when we pressed it. I then changed out Fuse 8 and Fuse 9 just for the heck of it. Knock on wood people.... it has been almost 3 days and car is working like a charm.