No low beam on 260z 2+2

[JPav_260z]

Hi, could anyone please help me with this problem? My park lights and high beams work but low beam doesn't. I've tested the headlights with 12v and can get both low and high beam to work, checked fusible link, checked fuses, checked connections at base of stalk switch and still can't find the problem. When I take out either left or right headlight fuse and turn on my high beams, then one goes to high beam and the other one goes to low ( ie take out the right fuse, turn to high beam and left high beam works but the right one comes on as low beam ) This is doing my head in and I can't think straight anymore, I might be missing something simple so just seeing if anyone can shed any light on this, cheers, John

[Zedman240®]

What year 260Z have you got? I used to lose my headlights over bumps and it was because of a bad connection at the fusible links that have that opaque cover on them in front of the brake master cylinder. Connectors and link wire look fine but were corroded at the spade terminal in the molded link holder. Rain water used to fall through the bonnet vents and pool in the link holders and corrode.

[JPav_260z]

Mine's a 76 model with no bonnet vents, have tested the links and they're fine, thanks for that

[JPav_260z]

ok, I've just had another look at the combination switch and know that it's definitely not the problem  as I bypassed the switch by joining the appropriate wires before the switch and I still get the exact same problem of no low beam. Where to look next?

[Riceburner]

Have you checked and cleaned the earth in front of the radiator support?

[JPav_260z]

No I haven't, just had a look and can't find any earthing points in front of the radiator support?

[maddos]

You'll probably have to disconnect the plugs near your radiator support and do a continuity check back to your light switch assembly. Remember you always have 12v supplied on one conductor and the earth is switched to the other two depending on whether high or low is selected.

[Riceburner]

I have a 73 240z and thats where my earths are... I just had a look at haynes datsun manual wiring diagrams and they show headlight earths near the horns on a 77 model so maybe try there

[xa1973]

 

 

I had the same issue on my zx

 

What globes and type are you running???

 

You might find if you are using after market high watt jobbies your system may not be able to supply enough power due to the wiring circuit and fuse limitations etc etc

 

I changed my whole system to individual ballast units per light

 

 

[maddos]

Or to avoid the "red herrings" pull the 3 way plug where your lighting cables join in front of your radiator support and check with a multimeter if you have 12v present when you turn lights on.

You're going to get 12v there between your high beam and gnd which proves fuses are ok.

Then if you aren't getting 12v to the other point in the 3 way you must have a contuity problem from your switch to this plug as you have already proven up to this point by bridging your switch. it's not a complicated setup with relays etc (unless someone has done the relay mod which would complicate your fault finding a little)it's just the fact that 12v is there all the time and gnd or negative is being switched to complete the circuit. So checking for a gnd point near the radiator is a waste of time.

[Zedman240®]

Check with a test light to make sure the switch is 100%. Make sure there is power first on the large white wire with red stripe and with the headlight switch "on" after the parkers, there should be power at the large red wire. Place the test light on the red wire and make sure that has power when the switch is turned fully.

[maddos]

Even if the switch is 0% it has been ruled out by bridging wires which lead to the switch.

[JPav_260z]

Thanks for all the feedback everyone, after conducting a continuity test I found that I the red/black wire going to the headlights wasn't getting switched to ground, the other end of that wire at the indicator stalk was switching to grouind fine so the problem was somewhere between. I had continuity from the headlights to the firewall so under the dash I went, found where this red/black wire goes into a black connector(C3) and that's where the problem was, it wasn't making contact within the connector, bypassed that connector and joined the wires together, problem solved, low and high beam both work now. Thanks again, now all I have to do is find out why I don't have hazard lights before getting the car inspected to change to special interest rego

[maddos]

Well done mate.

For hazards maybe check hazard relay as it is seperate unit to indicator relay.

I got a blue slip on my 260 on Friday (NSW) and they didn't even check hazards???

[stevo_gj]

Thanks for all the feedback everyone, after conducting a continuity test I found that I the red/black wire going to the headlights wasn't getting switched to ground, the other end of that wire at the indicator stalk was switching to grouind fine so the problem was somewhere between. I had continuity from the headlights to the firewall so under the dash I went, found where this red/black wire goes into a black connector(C3) and that's where the problem was, it wasn't making contact within the connector, bypassed that connector and joined the wires together, problem solved, low and high beam both work now. Thanks again, now all I have to do is find out why I don't have hazard lights before getting the car inspected to change to special interest rego

 

Bravo! Good to see you had a win. I once believed that it wasn't worth learning how to do this kind of thing myself but it's really not that hard, just takes a bit of time

[JPav_260z]

thanks, just took a lot of persistence and a lot of F bombs! Also found the $14.95 workshop manual on cd in pdf form off ebay very handy and has already paid for itself