issue with running lights

[StrokinIT]

Hey everyone,

I couldn't find any information on the exact issue I'm having, the only thread that seemed somewhat similar was the one started by Josh817, Help! Running lights are dead on my '72 240z, any clues? however our running lights aren't blowing fuses; although we haven't been able to keep the running lights on long enough for a fuse to really have the chance to blow.

 

So here is what I am experiencing. My running lights do not come on when the lights come on, they only come on when the brake pedal is pressed (whether the headlights are on or not). My dad and I think that we might have wired something wrong in the steering column, does that sound right to anyone else? Has anyone else encountered this issue themselves?

 

Thanks,

Josh

[dangerboy]

Do your brake lights come on when you press the pedal or are they always brighter when the lights are on?

[StrokinIT]

The brake lights only come on with the brake pedal pressed. The side marker lights and running lights only come on when the brake pedal is pressed, regardless of the position on the headlight switch on the column.

[Oddjob]

The brake lights only come on with the brake pedal pressed. The side marker lights and running lights only come on when the brake pedal is pressed, regardless of the position on the headlight switch on the column.

 

Your problem is almost certainly a bad or missing ground somewhere. When two seeming unrelated things happen like this, that is almost always what does it. To start troubleshooting, and get a sense of why this could happen, go to this discussion: Hazard Switch, and look at the drawings in post #1 and post #19. Good hunting.

Edited February 19, 2011 by Oddjob

[StrokinIT]

Thanks Oddjob, I will look into it. I had a hunch if it wasn't a direct wiring issue it had something to do with a ground issue.

[StrokinIT]

Ok, so I was finally back up at my dad's house this past weekend and we fixed the issue where the running lights only came on with the brakes. We think it was caused by using double filament bulbs where single filament bulbs should have gone. We put the proper bulbs in and not only are the brake lights and turn signals much brighter, but the running lights no longer come on when the brakes come on.

 

Except now, we can't get the running lights to turn on. We were messing with the wires in the combination switch on the steering column, and from time to time we would be able to get the lights on but pretty much anything would cause them to turn off, e.g getting out of the car, coughing, pretty much anything that would send any sort of vibration through the car to move any of the wires just the tiniest bit. We have the FSM for my 76 280z and I spent a couple hours looking through the wiring diagrams, and I thought I had figured out which wire was the one to control the running lights (Green with white stripe), but that didn't work.

 

Does anyone know which wire from the combination switch actually controls the running lights? I am back home now and will be back up to my dad's on Thursday night for a long weekend. I am planning on registering my Z this week and this running light issue is the only thing keeping it from passing inspection right now. I would gladly appreciate any and all help.

 

Thanks again.

[cgsheen]

Well, you were right - it's the Green/white wire on the combo switch attached to the lights/wiper/washer stalk on the right side of the steering column... "Supply" voltage comes in on the Green/blue wire - should be +12v all the time (lights will turn on without the ignition key being in or turned). You can check the switch by jumping the Green/blue and Green/white - see if the running lights come on. (Although the same Green/white sends power to the dash lights also - through the rheostat... If the lights in the gauges are working, the switch is working...)

 

Looks like Nissan ran GW for power to the rear markers and tail lights, and GL for power to the fronts... I'd check the wiring and connectors between the switch and the rheostat or there-abouts if NONE of the running lights work. Then you'd have to chase wiring through the car. Connectors and Grounds are most likely. One of the biggest problems in these Z's are electrical connectors - check and CLEAN them all. Including the lights and sockets...

Edited March 15, 2011 by cgsheen

[StrokinIT]

Thank you for that information, however I'm still slightly confused. The rheostat, is that the dimmer knob down and to the left of the steering wheel? The one that dims the dash lights? When we were checking these connections, it was generally my brother and I outside checking for the running lights to come so I do not know whether or not the dash lights even came on at all, but before when the running lights came on with the brake pedal, the dash lights never came on. Could it be that there is some interference at the rheostat? And if so, would I need to get behind the dash (or take it out) to get to it? Also, what do you mean by jumping the wires?

 

Sorry for the extremely simple questions, my car is currently 75 miles away and my dad isn't home so I can't have him check for me.

 

Thank you

[cgsheen]

You're correct about the rheostat - it's the "dimmer". In electrical terms, it's a "variable resistor" that can control the current going through it. The rheostat doesn't have anything to do with the running lights though (well... it shouldn't...). It's fed by the same source, but it's output only goes to dash lighting, and it's only purpose is to control the brightness of those bulbs.

 

Jumper:

A switch is just a way to "break" a wire. Hold the wire apart, whatever it feeds is "switched off". Touch the ends of the wire together, whatever it feeds is "switched on".

 

The switch on the light stalk has the GW and GL wires soldered to it. Take another piece of wire stripped at both ends. Touch one end of your little wire to the GW solder pad and the other end to the GL solder pad at the switch. That creates a "jumper" between the two wires. You've just bypassed the switch in the light stalk and powered the running lights directly by using your little jumper wire.

 

The only thing this checks is the running light switch inside the stalk. If the running lights work properly when jumped, the internal switch is bad. If they're still funky, you problem lies elsewhere - trace the power down the wire. Check the connectors near the steering column.

 

The bundled and wrapped sections of wiring are least likely to have a fault, unless you can see a cut, scrape, gash, pinch - obvious damage - to the wire bundle. Most likely to have fault are the connectors - especially under the dash at either edge of the windshield (most likely spots to leak water) - AND the wiring, connectors, at the front of the car. Pull those big connectors under the glove box apart and check them for corrosion.

 

EACH running light has a socket, bulb, wiring (power AND ground), and connector to the harness that needs to be thoroughly checked and cleaned. You may need to remove or disconnect ALL of the running lights and then plug them back in one at a time to find the fault...

[StrokinIT]

Thanks so much, I will try this later on in the week and hopefully I can track down the problem.