87 z31 headlights go up but not down?
 

Hey all, another mysterious problem has arisen with my z.

A few days ago i noticed a significant lag in the time between when i pushed the button and when my headlights would actually close (1-2 minutes), and now they don't close at all with the button. Ive manually spun them closed, then pressed the button and they come right up. What could be the problem?

turn the headlamps on ,they raise , turn off the key see if you can raise the lamps with the motor wheel further and raise them to the highest point . then they may work correctly if not usually a problem with the limit swt. in the motor assy.

they dont move at all when i turn off the lights or press the button. usually when they go down or up, the yellow light comes on for a second, but i press the button and nothing, no yellow light or downward motion

Anyone have any ideas with this? It's till happening. Is there a different control for lights up than lights down? Like a different relay or fuse or something?

I had a prob with mine (locked halfway up) and found that something fell into the space behind one of the lights, jamming it. When I cleared the path, both worked again. If your actuators are dead, I know where you can get replacements. Did you check whether you are getting power to the actuators when you hit the dash button & when you turn the light stick?

yeah, they go up from a down position just fine, with both the button and switch, they just wont go back down. theres nothing stuck there, the light on the button doesnt go on when pressed to make them go down... the spin down manually smoothly and fine, i just have to open the hood and spin the motor's knobs,which is annoying.

If you get the same result when you push the dash button/turn the stick both multiple times - I'd say it is your actuators telling you they are tired. Time to retire them. Or that's what I would do first. Though it is a little strange that they both die at the same time. Makes you wonder...

So... Our good buddy rogerz also wants you to check out your whole alternator/battery/cables deal. You would be AMAZED at what totally screwed-up wacky stuff happens when you are not providing your Z's electronics with the absolute OPTIMUM power supply. Seriously. Before you replace your actuators, check out your whole power supply game. You may find a weak link in that and save a buncha' work. Your Z is lunatic picky about non-stop volts and amps and just acts weird without 'em. Check all of that first. If you are getting 14v+ alt charge and have a good, newer battery taking it in and cranking it out - AND all your connectors are clean and tight, your electronics should be happy. It's safe to blame the other gadgets then.

There is another solution here: Do the mod where the lights go on with the lids down.
I had that on my 88 and was very cool. I am tempted to do it again on my 87..I just have to recall which wire gets disconnected. The only time I got flack was when I went for inspection and the guy yelled "Hey, how do you raise the lids?" just pull back on the high beams and they pop up..or hit the switch. You will loose some radiance but gain coolness.

Yes, i have done this, and reconnected it once this happened, thinking it was the cause of the problem... I live in MA, and especially with the weather we have had recently, i need the visibility of them being up, but still able to go down

Yeah its weird, doesn't it take more effort to bring them up than put them down? They come up quick and easy and equally, but don't even make an effort to go down. It cant be the battery, battery cables/alternator as the battery and cables were just replaced, and the volt meter in the car (and my multimeter) read 13.5-14 when running. How can i test actuators?

By actuator I mean the motorized gadget that raises and lowers the light housing whenever it's told to. Wondering if you ever tried to lower them when they were frozen UP. Could have stripped something, like the top tooth of the gear that would lower them now if it could. That's what it sounds like when you say you used to push them manually to get them to go down.

Don't know what else to tell you. If it weren't winter, you could get a couple of those 'actuators' from a recycler and pop them in to see what happens. As long as you have headlights until spring, I guess you can wait. Or borrow a heated garage. Maybe somebody here has taken that whole assembly apart and knows what is in there. I haven't. Am checking FSM.

Yeah, FSM shows a motor for each. For '86, it's in the EL section around pages 51-53, etc. There's a whole procedure for checking everything out, including the controls. Check your '87 FSM. If you are good with your multimeter, you might locate the glitches. Looks to me like the motor/control arm set-up should work both ways if its working in one way, i.e., if it goes up it should come down. Motors are probably good, that means.

And, no, according to the diagram, it should not take more effort to raise them than to lower them. Looks like a push-pull action from the little motor.

Did you try the adjuster wheel ? under the boot on the back of the door motor note watch the fingers around the door or ..smashy smashy

also undo the motor and check the torque to move the door up and down pivots may be rusted tight.

Good point about rusted pivots. Or just restricting movement for some reason. Didn't think of that.

Let us know what you find. The motors may be designed to shut down or reverse if there is any obstacle to free movement, like the garage door closers that refuse to cut your leg off if it's in the way.

the pivots are not rusted, i spray them every so often in either wd 40 or pb blaster. i did not just "push" on the buckets. each light has a separate motor, on the back of which is a wheel that brings the lights up and down manually, you just have to turn by hand.

i think the problem is electronic, not mechanical. i just hate chasing electrical problems, so i figured id ask to see if anyone had already found a solution before i went digging further once it bothers me enough.

Well thought it was worth checking carefully
In the mid to late eightys I worked on 5 or 6 retractable H lamps z and pulsar at the nissan dealer with problems 2 of them were rusted pivots at 3 yrs, so rust might well be the culprit at 35+ yrs mine rusted yrs ago and acted as you described

the "Adjuster wheel" is to set the correct position of the lamps limit swt for proper function as well as giving a way to manually operate

the limit switches are in the motor :014:

hoping somebody sees this, I'm having a similar problem where my pass. side works perfectly with both button and multi switch, and my dvr side motor seems to be out.
all fuses were good, i checked the motor electrical unit (unknown name) thats over by the pass strut mount. thats good, and as far as i can tell the relay is working (swapped out 5 and nothing changed)

how do i go about testing the headlamp motor itself? currently it sits on the engine, so i know it's not a rusted pivot, everything is connected and i know the limit switches in the motor are there. when rotated by hand, if the light isnt in position the press button switch on the left side of the wheel will stay lit until rotated by hand into the correct position.

can i apply power and ground directly to 2 pins of the connector to test it?
86 z31 NA 5mt GLL if it's not in my sig.

Joezmam367 did you ever figure it out? I'm having the same problem

The head lamp bucket has to be all the way up for it to be powered down,like the pivot is rusted etc it gets tight and stops

Im having the same problem, did you figure it out? The button light stays on 24/7 even when the keys are out the car. I was thinking electrical maybe.