leo1254

I woke to a dead battery. Recharged it. Started the car, and noticed the meter read slightly negative. Battery was bought in Oct07.

Purchased a new alternator, and installed it myself (I am not a mechanic) Parts store clerk said it was bad.

It started right up, dash meter indicated a positive charge. Drove for about 8 miles and put it in the garage. I didn't notice the tail lights being on at this point. (pretty sure I would have)

Today I got in the car, and the battery was dead..(just as it was the day prior). Put the charger on "start" to jump it, and the tail lights were on. Turned off the key, (still charging) noticed the tail lights still ON! Took off positive terminal of the battery. Disconnected pos term., and found this forum.

Previous post here talked of a switch at the brake pedal. I dont think this is the problem. Would sure appreciate some help, Its my only means of transportation.

qldit

Good Morning leo1254, although you don't suspect that the actual pedal switch is causing your problem, I would suggest in reality it actually is.

This is really all that can cause that.

Chances are it's contacts are welded together or the switch is misrigged.

Get a decent torch, remove the underdash cover if needed and put the drivers seat back and lie under that dash and have a good look at it.

You may have more than one switch operating off that pedal arm, one may be cruise control and there could be another as well as the stoplight switch.

Identify which is actually the brake lights and you should find you can operate it's plunger with your finger and turn the stoplights on or off.

Plunger fully extended is usually "lights on".
Pedal arm in return position generally depresses that plunger marginally.
The switch is generally movable by adjustment to allow proper rigging.

If the lamps don't operate "off", remove one of the spade electrical connectors from the stoplamp switch and that should turn them off.

If they go off in this circumstance replace the switch and carefully re=rig it.

These switches are generally an all plastic kind of construction with the plunger extendable a couple of inches and easy to replace.

You should have no problem with this task.

In some instances there maybe a plastic bracket on the pedal arm that may be used as the contact face for the switch plunger, in some instances these can break and actually allow the stoplights to remain illuminated because the switch has lost it's operating face, so the switch plunger can remain fully extended.

Others will have different ideas.

Cheers, qldit.

leo1254

Thanks qldit!
Just got your message. I disconnected the battery entirely, put a multi-meter (set to audio continuity buzzer), I connected to the battery cables, and had continuity. While buzzing, I pushed the plunger and it stopped.

I think this problem ruined my battery. Possible? Could it have done any other damage? It is slow charging now, and will charge through the night.

Again, much hanks for your help. I will replace the switch, and repost the results

qldit

Good Evening leo1254, my pleasure old chap, with regard to the discharge damaging anything, there should be no problem, what actually happens is that the battery simply discharges completely, this is similar to doing a battery test.

Where the problem arises is that the battery needs to be carefully recharged with the vehicle terminals disconnected, (or at least one of them) because the increasing voltage of an external charger may affect the alternator regulator system.

Other problems may occur with the radio security code being lost or a anti-theft system encoding being lost. (if the vehicle has one)

Apart from this kind of thing it is a simple case of carefully charging the battery, addressing the switch problem, (possibly rigging or contact plate) and ensuring all is OK and the battery is correctly fluid filled before reconnecting it.

This process should return you to proper integrity and no further problem.

When you have everything proper, run the engine at a stiff idle and confirm the voltage across the battery tops out at around 14.4 volts approx., after several minutes running.

If this voltage is not reached you might mention and we can possibly suggest further investigation, but I think you have nailed the problem and should have nothing further.

You would now appreciate that the stoplight operation is quite simple, power originates from the fuse panel, passes to the stoplight switch then dependent on the switch making contact powers the lamps. These are probably 21 watts x 2 = 48 watts which will easily deplete a battery over a period.

Stoplight switches being mis-rigged or internally having a problem is quite common, similar kinds of problems also happen with trunk interior lamps.

Did you determine that the switch was actually being operated by the pedal returning, it sounds like you may have only needed to adjust the switch positioning so that the switch was opened when the pedal was not depressed.
In some vehicles there is a plastic bracket on the actual pedal that operates that switch and that plastic bracket my be damaged or missing, but all vehicles follow a similar idea in this regard, the switch plunger usually abuts the actual pedal metal.

Interesting learning experience for you.

We all have been trapped by these kinds of problems at one time or another. LOL!!

Best of luck,

Cheers, qldit.

leo1254

Hello qldit.,
Thanks to you, this has been resolved. My whole problem was due to the nylon pad which the switch actuates against becoming brittle due to age. It broke gradually, and once it fell out...... it left a hole which directly lined up w/ the switch plunger.

Because the part store didnt have the exact replacement, I fashioned a small piece of wood of the same size and wrapped it with good ole black electrical tape. It will last longer than the original part!
You were a life saver my friend, and I truely wish you the best I love the net!!
G'day!

qldit

Good Evening leo1254, thankyou for your feedback, others will also appreciate it.

Very well done my friend, the pleasure is mine, your ingenuity and ability fixed the problem once you a pionter.

Yes the internet and this TSF site in particular is incredibly useful, I am amazed at the wealth of highly experienced and decent chaps even in this area alone, we are all constantly learning from each other in a really decent kind of environment.

Cheers, qldit.

Midnight Tech

This seems to be a common item on Nissans of this vintage. My 87 Hardbody did the same thing - took a small bolt and put into the hole and let the plunger contact the head of the bolt. Worked like a charm!

qldit

Good Morning Gentlemen, that is handy to know MT, must remember that one, TNX.

Cheers, qldit.