Gauge lights not working, only some.. not all...

[Shawninvancouver]

74 260,  tach light and heater panel lights work..  no speedo or all 3 gauges/clock not on... does this mean is just dead bulbs if tach light works ok? or can it be something else?

also turn signal lights dont work, or e brake light... are they just all dead??

Edited July 9, 2021 by Shawninvancouver

[Jeff Berk]

Hi again... I don't expect all your dash lights to be dead at the same time. Lets look at your dash lights for now.

1) Turn the lights on and check if there is power to the hot wire going to the variable resistor (a.k.a. dimmer switch) to the bottom left of the dash. The plug should be a three contact with only the top/bottom contacts used (http://www.vintageconnections.com/Content/images/products/66/1.jpg) This will tell you if power is getting this far. 

2) If you have power, try jumpering the harness wires at this connection to bypass the resistor. If the lights come on, you likely have a bad dimmer switch. If not, AND there was power to the switch, you'll have to start testing the connections at the bulbs sockets. That will at least give you an opportunity to see if the bulbs are burnt out.

BTW: The URL for the connector picture is from Vintage Connections. That is likely the best place to purchase replacement connectors for your 260z. 

[Shawninvancouver]

Got ya.   I was told all bulbs are in sane circuit. So if tach light works all lights should work.  Could the dimmer switch be sorta bad ? Allowing power to tach but not gauges?? 

[Jeff Berk]

Your thoughts are correct; however, your wiring has undergone several iterations of tinkering. There is a potential that someone did a little rewiring. Or, you could be right that all the other bulbs burnt out. I'd like to see how far the power is getting first.

How original are you trying to keep this car? I ask because you might consider replacing your bulbs with LEDs (which is not as easy as plug and play).

[siteunseen]

Mine went out and I had to flip the 2 plates over in the combo switch. Years of off/on contact had burnt those plates. Turn them over and they're like new.

Rebuild_240Z_combo_switch-1.pdf

[Jeff Berk]

Siteunseen:

I had to do likewise, then installed the relays to prevent further damage to the switch since the flip method only works one time.

I'm assuming Shawn's switch is providing power since he didn't mention anything about headlights or parking lights.

[siteunseen]

53 minutes ago, Jeff Berk said:

Siteunseen:

I had to do likewise, then installed the relays to prevent further damage to the switch since the flip method only works one time.

I'm assuming Shawn's switch is providing power since he didn't mention anything about headlights or parking lights.

I was on my phone but now that I'm on the laptop with all my pictures I can see the headlight and parking light solder spots and wires from a long time ago. Thanks for the push.

Edited July 9, 2021 by siteunseen

[Shawninvancouver]

My head lights and park lights are ok.  The park lights are finicky with the combo switch. But my tach light works but no speedo no turn lights on dash no park light no three gauges lights on dash. 

[bartsscooterservice]

contact oxidation could also be. Just grab a multimeter and check for voltage and ground

[Jeff Berk]

2 hours ago, bartsscooterservice said:

contact oxidation could also be. Just grab a multimeter and check for voltage and ground

Add to that "Spray each contact you check with DeoxIT or other contact cleaner".  Be careful since the circuit is energized and you might need to have some spare fuses on hand.