200sx project

Well, the 200sx is coming along slowly but surely,

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(no new pics yet). I've taken out the Cobra bucket seats and replaced them with a pair of original seats. Replaced the entire boot lining and carpet as the original was falling apart. Replaced the broken electric aerial timer unit. Replaced the passenger side door as the original was split! Plus loads of other small jobs that needed doing. The only things stopping me from getting the car lowered and then resprayed are the bloody headlights. They still won't retract despite of everything I've tried.

I've replaced both headlight units including motors, replaced the headlight timer unit, all four relays connected to the headlight system, the dim-dip unit and the headlight control stalk. I've checked every fuse connected to the lighting system and every wire for possible breaks or deliberate splicing and turned up nothing. As far as I can tell from the wiring diagrams everything is as it should be and there is no reason why the lights shouldn't retract, but they won't. It's doing my head in now.

If anyone has any experience with the 200sx lighting system could they please give me some ideas?

Thanks,

Andy

Reply to
Comfortably Numb
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About the only bit you haven't replaced is the retract switch on the rhs of the steering wheel. To check just unplug it. It pulls out with a firm tug.

Reply to
Peter Hill

Not with that car, but my old TR7 has motor lights. Can you upload the wiring diagram to a website somewhere? Might be able to shed some light... ;)

Reply to
Questions

Sorry to check, disconnect, link pins 1 and 2 (sky blue and green) on plug. If it works the retract contacts in the switch are not working.

Other thing to check are diodes - strapped up in a bundle behind stereo and heater.

Reply to
Peter Hill

Thanks for the reply.

I just replaced this switch today and still nothing :-( I honestly don't know why they won't retract. I guess my last chance is to pay an auto electrician to take a look.

Reply to
Comfortably Numb

Replaced this switch today and linked pins 1 and 2,. still nothing.

Checked these a couple of days ago and they're fine. I'm at my wit's end with these headlamps!

Reply to
Comfortably Numb

Reply to
Comfortably Numb

I believe you can wind them down manually... tried doing that, and then seeing if they pop back up?

The other vague possibility is someone has tried to go for the 'sleepy eye' effect, but hasn't set them up properly, and this invariably involves a box of tricks of some description being wired into the system - anything apparent on this one?

If all else fails, register with the forum at

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and pick the brains on there - top club, even if the moderators can get above their station at times! ;-)

Reply to
JackH

Bloody OE.

The wiring diagrams are available here in PDF format if you would like to take a look. I'd really appreciate any help you could offer.

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Thanks.

Reply to
Comfortably Numb

Ok, I'm looking at main_wiring1 and on the mid left is the LH headlamp motor.

It's pretty similar design as in my TR7, the same motor makes the light go up and down, switches stop the motor in different positions, and you make the lights rise or fall by supplying +12 to either one of the control lines, i.e. to the left wire at the top to make the light retract, and to the right wire at the top to make it extend. The motor runs, until the physical action causes the switch to cut power from the supply to the motor. Simply put, the whole thing only needs to be earthed and then +12v to the "retract" connection should cause it to retract until it reaches the down position and turns itself off. Similar, supplying the power to the "extent" connection instead should cause it to rise until it turns itself off in the up position. Power to both should make it keep cycling up and down continually.

There is a Retract Relay 3 (R3) , and 4 (R4). There is a Headlamp Timer unit (HTU I'll call that.) There's some other stuff that no doubt does things.

The HTU controls the Retract function by means of R3. When it earths the wire to pin 6 the relay energises and connects the "retract" wire from the lamps to the output from R4. If R4 is un-energised, this should be a +12 volt supply, if energised, then it should be an open circuit.

When the HTU is not earthing R3, the retract wire should be being earthed.

To test this, I would go as follows:

1) disconnect the headlamp unit from the control loom - four wires this should be - so that I wasn't shorting out via R3, and deliver +12v onto the "retract wire". The lamp should retract. Move to the "extend" wire and the lamp should rise. I'm assuming there it will earth though the bodywork, this might need checking. If it doesn't go up and down like this I'd need to understand why.

2) Having ruled out the lights themselves, I would plug them back into the control loom, and connect a multimeter from the "retract" wire on the most remote of the two lamps and see what I had there. The ignition / lights are still not turned on at this point. If this is earthed as expected, I would disconnect the HTU in case it doesn't like being shorted out and earth the other side of the coil on R3, energising it. The point on the retract wire should now go to +12v, and if the lamp wasn't already, it should now retract just as when I tested it a moment ago with +12v to the same point. If not then something is limiting the current so that it isn't able to drive the motor properly. If this does all happen, chances are the HTU isn't energising the relay when it is supposed to, either due to a broken wire from pin 6, or to a faulty HTU, but see below.

3) If the wire goes open circuit instead of +12, I'd think there was a break in the wire, either between R3 energised-input and R4 un-en-output, or between R4 un-en-input and the supply going to R4 en-input.

4) If the wire is open circuit all the time, I'd suspect a break between R3 output and the headlamp units.

5) If it stays earthed when I energise R3 then it's faulty, plus I suppose R4 could be stuck in the energised position which would mean the lights wouldn't turn off or sommat, maybe think about how that might work if none of the above has found a problem that fixes it.

With the HTU, it doesn't merely earth R3 whenever the lights are off. One function is to ensure the lights are turned on when they're already retracting, and another is to raise the lights when you operate the flasher lever but to keep the lights raised for a while, in case you want to flash a few more times, rather than just the once.

There are probably other functions and it receives various signals e.g. the headlamp units send +12v to pin 8 while they are actually lowering, and to pin

1 when they are actually rising, and no doubt there is more going on inside. Therefore, if the HTU isn't pulling R3 to earth it may mean there is a wiring fault in the circuits to the HTU, instead of a faulty HTU. Need to think about how that works in detail to suggest what might not be happening.

Hope this makes some sort of sense.

Reply to
Questions

Thanks for taking the time to have a look at the diagrams and writing your reply. I'll try to check out everything you mention, this weekend. I'll post back here as to the results.

Thanks again.

Reply to
Comfortably Numb

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