I need everyone's help on this

[zdude1967]

I have a short or something going on that when I pres the brake pedal  the sidemarker lights and the dash lights come on in addition to the rear brake lights. Also when I have my headlights on the turn signal for the left signal lights up ...Anybody have an issue like this and how did you fix it.

 

 

 

Thanks 

[Patcon]

Check all of the chassis grounds

[SteveJ]

Take out the 1156 bulb. Put in the 1157 bulb. I'm guessing it will be the bulb circled in the lower right of the attached wiring diagram.

 

Edited March 20, 2017 by SteveJ
Replaced wiring diagram

[SteveJ]

I did forget one other possibility. The insulator in the 1157 socket where I circled could be cracked/broken, allowing the contacts to touch. That would result in the same symptoms. I have experienced that before.

[Diseazd]

1 hour ago, SteveJ said:

Take out the 1156 bulb. Put in the 1157 bulb. I'm guessing it will be the bulb circl

So nice to have an Electrical Engineer on our forum.......especially when I know so little about the science.....all I really know about electricity is "it bites you, but you can't see it". Take care of yourself Steve.....we need to keep you around!

[Zedyone_kenobi]

Amen to that!  Electrical Gurus like Steve and Zsondabrain who help out the community are irreplaceable.  I am a mechanical engineer, and if it gets beyond Ohms or Kirkaffs law, I am out. As far as I am concerned it is all magic. A bunch of invisible things running around moving things and lighting things up.  It is voodoo.

[SteveJ]

Don't forget about @Zed Head and @Captain Obvious. They are on top of a lot of the electrical threads.

Heck, I appreciate all of the information provided by others, too. You don't see many questions from me because I have been reading here and find my solutions frequently before I have the problem. I just try to store away as much information from this site as possible.

[zdude1967]

Steve J- so it is not a short it is rather the wrong bulb on the drivers side taillight? Am I understanding this correctly?

 

Z dude 1967

[SteveJ]

By definition, a short is bypassing the load on a circuit, so you never had a short.

A cross-connection is a connection between circuits that should not exist.

Bleed over is you backfeed a circuit due to a poor/lost source or ground. (An example of that is the dim headlight caused by a blown fuse.)

What you have is a cross-connection. It can be caused by using the wrong bulb. It can also by the contacts in the bulb coming together due to a failed insulator. A less likely scenario is corrosion or metallic debris in the light socket.

The bulb is easy to diagnose. Remove the bulb. If it has one contact on its base while the socket has two contacts, there's your problem. 

Unfortunately you give no background on your problem. Is the car new to you? Did this just happen? Did it happen after you changed a bulb? You also don't say what year car you have. I made the assumption that you have a 240Z since the symptoms you described fit the circuitry of a 240Z.

[SteveJ]

As a follow-up, I took a moment to look at your profile. You have a 260Z. Yes, the possible causes I listed earlier can happen on a 260Z. I had a failed insulator in the left rear socket, and it caused a cross-connection between the brake lights and running lights.

[zdude1967]

Steve J

 

Thanks for the info. Yes, it is a 260z, I have had it a few years and the turn signals never worked on one side. I have replaced the turn signal switch, flashers, and hazard switch. Recently I took out the taillights etc to prep for paint . Once I put it all back together the combo switch connector melted a bit. at that point I noticed that when you press the brake pedal the dash lights and side marker lights go on, turn signals still only work on one side ( drivers) and when the headlights are on the passenger side turn signal indicator on the speedometer lights up and the turn signal that did work does not. This has been such a major pain to the point I began trying to remove the dash thinking maybe wires were melted together thus causing the dash and side markers to light when the brake is pressed. Finally the other day I came to the reality that if I (at my skill level) took the dash out many other things would probably never work again. I have no shops in my area (Phoenix) that work on these so I felt it could be the end of my ever driving this car again. 

 

I am going out to the garage this weekend to check out the bulb situation. 

 

I will keep you posted .

Thanks

Zdude1967

[SteveJ]

@borini63 - Do you know anybody in the area that could help him?