510 wagon headlight issue

[slamurai]

1971 510 wagon, L16 with auto trans. All electrical was working fine before.

Going to store a few nights ago, headlights on, no issues. While driving, I honked my horn and the headlights turned off. Kinda scary but thankfully the previous owner installed cool yellow headlights mounted inside the regular lights with a seperate switch and was able to safely get back home.

Checked fuses and headlights with a tester, all good. Anybody have this problem before? Looked at at wiring schematic but I might as well be reading a foreign language. Hoping for somone to say, "oh yeah, that happened to me and it was a quick easy fix. All I did was xxxxx" Thanks for any help and suggestions.

[flatcat19]

Are you getting 12V at the headlight itself?

 

Continuity with ground?

[DanielC]

Remember 510's use switched grounds to control the headlights.

[slamurai]

Just got done checking things that I think I know how to. No power to the headlights with the headlight switch pulled out. 0 volts to the headlights and fuses with car running and switch on. Alt is putting out 14.2 volts. Leading me to believe its under the dash or maybe the headlight relay. Getting dark, will try again tomorrow

[Lockleaf]

Do high beams work?

[DanielC]

The headlight switch DOES NOT supply power to the headlights.

The headlights are always hot, power supplied to the common terminal on the lamps.   The headlight switch completes the ground circuit from the headlights, through the headlight relay. 

[datzenmike]

Check the RED (right side) and the RED/BLUE stripe (left side) wires on the headlights. These both go to 10 amp fuses in the fuse box. You should have power to them both.

 

As mentioned the relay just selects HIGH or LOW beams so if the relay isn't working, one of these (HIGH or LOW) has to be on. To have low beams you have to have parking lights working. Without parking lights working the relay is not powered and it stays in the OFF or HIGH beam position.  

[Doctor510]

Yjere are TWO black ground wires coming out of the HL relay, tie them together and reground them.

[Big_E-Dog]

i wish i knew this before i completely rewired for hid/led. nothing was adding up so i said fuck it lol!

[datzenmike]

Yjere are TWO black ground wires coming out of the HL relay, tie them together and reground them.

 

Absolutely. I agree, if the ground has failed this would prevent either HI or LOW beams. It's a better fit than both fuses blew.

[slamurai]

Yjere are TWO black ground wires coming out of the HL relay, tie them together and reground them.

[slamurai]

Thanks everyone. Both black wires from HL relay are still connected and screwed onto the voltage regulator flange. Looks good.

 

Checked high beams and they worked! Turn lever stalk pushed to the front. No low beams. All parking lights work. If low and high beams are from the same headlight, why did Datsun put another set of lights where my cool yellow ones are?

[flatcat19]

Why kind of rewiring was need for an LED conversion?

LEDs should be plug in.

 

If you can't figure out a bad ground-you shouldn't be mucking up your wiring even more.

[slamurai]

Ok. With the car off, the 20a horn, 20a park tail and 20a common all have 12.8 volts. The 2 10a headlight fuses have 0 volts.

 

There is no voltage at the red and red and blue wires at both headlight plugs.

[slamurai]

There was no LED conversion done, dont know where you got that. PO installed regular headlights with a yellow tint. Just trying to fix whats broken. Thanks for your help, i think....

[flatcat19]

There was no LED conversion done, dont know where you got that. PO installed regular headlights with a yellow tint. Just trying to fix whats broken. Thanks for your help, i think....

 

 

i wish i knew this before i completely rewired for hid/led. nothing was adding up so i said fuck it lol!

[slamurai]

Ahh, got it. My apologies

[datzenmike]

Thanks everyone. Both black wires from HL relay are still connected and screwed onto the voltage regulator flange. Looks good.

 

Checked high beams and they worked! Turn lever stalk pushed to the front. No low beams. All parking lights work. If low and high beams are from the same headlight, why did Datsun put another set of lights where my cool yellow ones are?

 

 

Ok. With the car off, the 20a horn, 20a park tail and 20a common all have 12.8 volts. The 2 10a headlight fuses have 0 volts.

 

There is no voltage at the red and red and blue wires at both headlight plugs.

 

 

This is mutually exclusive. You can't have headlamps without power to them.

 

 

 

It's a four lamp system. The two outer lamps have a HI and a LOW beam in them. The two inner lamps are HIGH beam only.

 

On LOW beam only the 2 outer lamps light the LOW beam filament.

On HIGH beam, the LOW beams turn off and all four HIGH beam filaments light for better visibility.

 

Painting the inner lamps yellow was a stupid fad a few years ago. It only reduces light output.

[slamurai]

So working backwards from the headlights to the fuses with no power, could it be assumed that either my turn signal stalk or headlihgt swtich be bad?

[datzenmike]

You said your high beams worked!!! and you said it was converted to LED. Be more clear..

 

You better post a picture of everything because someone must have re-wired things.

[slamurai]

Thanks for the lighting explanation, it now makes sense.

 

To be clear, I never said anything about LED's or HID'S or STD's. PO did rewire the inner headlights to a seperate switch under the dash as stated in the first post.

 

All I need to do is figure out why i have no low beams. Looks like the PO might have screwed things up by adding the switch to the inner lights. Thanks again everyone, will try and educate myself with a wiring schematic i downloaded.

[Lockleaf]

Remember, it's a ground switched system. One power, various grounds.

[slamurai]

Lockleaf, only the 2 outer high beams work, no low beams. The inner lights are on a switch mounted under the dash and work, dont know if its high or low beams but they appear to be wired as an independant system with their own switch.

[banzai510(hainz)]

ok you guys are driving me nuts,

1st off orginal owner was a dumbass to switch the inners only Why? when you got the outers that does the same thing. reson is they think it cool.  I can see maybe bumber lights separate from the whole system.

 

if you get HIGH beans on all 4 lamps then I think its the relay.  open up clean contacks an hopefully it works. 510 had to 2types that I know of. a relay with the harness connector and one the was just the relay. swap them if possible.

 

 

Now get a test light or a volt meter.  ground the one end to the car chassisi.

 

Now with the swtich OFFF!!!!!!!!!!!! you should get 12volts on each lug terminal (all 3). then when light switch is pulled one should go to ground then on HIGH another one goes to ground). other that was ground will get now 12v.that means your test lamp will go off or read zero volts when grounded. If yes then I say its good and you lamp is bad.  But chances of both lamps bad is rare. But has happen to me.

If no 12volts replace fuse and or wiggle and clean connctors at the fuse box relay ect.....

 

 

on stock 510 lamps(5001) both elements are 35 watts. So the outers that I seen are same watts just use another element unless you use a H4 lamp/

 

oh if you measure across the fuse on the lamp circuit your not going to measure anything but ZERO.   

[datzenmike]

Got it now, someone else's comment.

 

So the wiring has been tampered with and discussion of unknowns isn't going to help much I'm afraid.