Hello and Please Help me with my 280Z

[Captain Obvious]

Sounds like the alternator is fine. As for the rest of it, welcome to the world of old car electrical systems. A lot of that stuff in your list could be related to dirty electrical connections. I'd disconnect the battery and then using the wiring diagram, I'd trace the items that are giving you problems and clean all the involved connectors.

 

For example... I had troubles with my turn signals and traced the issue to one of the connectors by the passenger's left foot that made connection to the center console. The turn signal connections go into the center console because that's where the hazard switch is located. based on some staining in the area, it looked like my previous owner had a heater core leak sometime in the past and the liquid dripped down onto the wiring in that area and dirtied up some of the connections.

 

Your issue might be different, but that's the kind of thing you're looking for.

 

And about the brake warning lamp... I respectfully disagree with S30Driver above. The connection from the parking brake CLOSES to light the lamp, so if the wire is off, the bulb will stay out regardless of the handle position. It's a lot harder to get the light to stay ON due to a problem at the handle.

 

For the brake light, first thing I would check is make sure you have the two wires that go to the underhood inspection lamp and the brake warning switch going to the right places. Those two items are up by your brake master cylinder and your windshield washer bottle. If you switch those two wires around, the wander lamp won't work and the brake warning light will be lit all the time.

 

Not that I've ever done that or anything......

 

The wires are probably dirty and difficult to determine the colors, but if you can, the wire to the lamp should be blue/white and the wire to the brake warning switch should be green/yellow.

[siteunseen]

There's also a wire under the passenger's seat you can unplug to turn off the brake warning light but still allows it to work when your E-brake is up. I did it to my '77.

I just remember how I found that info. It connects with a floor temp sensor connector. sblake01 posted it, IIRC.

Edited May 13, 2015 by siteunseen

[rossiz]

i wouldn't advise on totally disconnecting the brake warning light - mine was very useful when i had a leaky brake line, and i'm happy it performed its function. the rubber hoses that go from the chassis hard lines to the wheels get mighty crusty over time and when they start to weep you will slowly loose fluid, maybe so slowly you won't notice it or see drips. there are floats in the master cylinder caps which trigger the light to go on when the level gets too low.

[Zed Head]

 

- The bright, red brake light at the bottom of the speedometer (in fact, for some reason this is on continuously)

 

Not sure when Nissan added the sensors in the brake fluid reservoir caps.  I know that 1976 didn't have them.

 

The light is a warning light.  If it's on continuously it's warning you that something is wrong.  So, the thing to do is to go to the Brake chapter of the FSM and see what could be wrong.  If the brakes aren't bled fully, the light will stay on.  If one of the reservoirs is low and you have the sensor caps, the light will stay on.  If the parking brake lever is engaged, the light will stay on.

 

That's what I would do first.  Heed the warning.

[Zed Head]

And ll of the other stuff in Post #23 should be described in the Body Electrical chapter.  Shows fuses and wiring diagrams.  Now that you're using the meter you can go crazy with it.

[SilverSurfer]

"The light is a warning light.  If it's on continuously it's warning you that something is wrong.  So, the thing to do is to go to the Brake chapter of the FSM and see what could be wrong.  If the brakes aren't bled fully, the light will stay on.  If one of the reservoirs is low and you have the sensor caps, the light will stay on.  If the parking brake lever is engaged, the light will stay on.

 

That's what I would do first.  Heed the warning."

 

My mechanic had just replaced ball bearings (front), rotors, and brakes on the front, pads on the back, and bled everything. Basically everything 'brake' related is new and properly taken care of. So, I am not sure what "warning" to heed here.

[Zed Head]

. Basically everything 'brake' related is new and properly taken care of. 

Except the light.  Your mechanic should have checked that also.  It's part of the system.

[Patcon]

I believe most of the areas that can light the red brake light are normally open switches. That means one is closed. A simple test for narrowing down the issue is to start disconnecting the possible culprits. Pull the wire at the parking brake switch, check the light, pull the connectors at the master cylinder, check the light. Keep doing this until the light goes out. I would have to look at a wiring diagram to know where they all are. By process of elimination you can figure out where the problem lies.

[Zed Head]

That's a good method.  One of those wires is on the pressure differential switch just below the master cylinder.  Could be the brake warning lamp check relay that site mentioned (indirectly) also.

[SilverSurfer]

Okay! As I am learning all of this, I went out and purchased a circuit checker (one of the ones that both lights up and beeps) and decided to do a test. I removed the covers to my fusible links, removed one of the links, turned the key to "ON" and used the circuit checker on it, connecting the one end to one 'peg' and touching the other. As expected, the light came on and it beeped. So far, so good. However, when I did the same to the second link, I got nothing.

 

Here is a photo to show you precisely which link (it is the red circled one):

 

 

I know the set on the right has a ground (the big black link), but does the back one on the left also serve as a ground of some kind? Or should it also produce a light/beep on my checker?

[Captain Obvious]

You didn't get any current flow beep on the circled link because that one is for your headlights. Nothing flows through that link unless the headlights are turned on.

 

Also, something to keep in mind. Just because it's black doesn't mean it's ground. The largest black link for example... Neither end of that link goes to ground. One side goes to your alternator and the other side goes to your battery. No grounds there at all.

 

I'm not sure you're using the circuit checker properly.

 

Where are you located? Anywhere near Philadelphia?

[gwri8]

The brake light issue drove me crazy on my 1/77.  I read all the threads, checked all the wires and connections, bled and re-bled the brakes. Mine came with the wires for sensors on the brake fluid caps but no where to connect them.  As Zed and Site mentioned, there is a relay under the passenger seat.  It tends to get cooked if there has ever been an alternator issue. They are also NLA and not really made to open easily.  There is a thread somewhere on here about how to re-wire a relay from 78'  (still available) to function in it's place, although it is not for the inexperienced. I'm lucky enough to have a neighbor who is an electrical engineer to rewire one for me for the price of two Sam Adams.   All said and done,  not until I replaced my brake master cylinder did it solve the problem.  The brakes seemed to work fine but the inner seals were mush.