StratfordShark

Hi,

I know the 3 position headlight aim pots were only on the Euro spec cars (mine's an 88 S4) but maybe someone here can help?

I don't see or hear anything when I operate the pot next to driver's seat, though almost every other electrical system on my S4 operates fine.

Have looked on the wiring diagrams (Sheet 1 'Lights Row' for MY 90 where the pot first appears) but I can't see any 12V feed to the pot or the adjustment motors, or any connection between the pot/motors and any fuse or relay. If I could find such a connection then it may be a start with tracing the problem of non-working level adjusters.

Are the aim circuits not fused? Are they not connected to the big headlight relay in any way? How do they get their power? Where should I look to get them going - maybe the earth point indicated for them on the diagram? Am I missing something obvious in how to read the wiring diagrams?

Thanks for any advice on this obscure area of 928s!

Adrian

88 S4 Marine Blue

SharkSkin

They are not electrical -- they are hydraulic and operate by moving a silicone fluid around, which I'm sure has long since leaked out.

Bill Ball

They were electric in later models, such as the 88. [EDIT: WRONG - probably just 90+] If this is a Euro that was federalized, the H4 lamps would have been replaced with DOT H5. These will not pivot. Most likely the motor was disconnected as well. You would need to buy H4 lamps, at the very least. The H4 lamp housing includes a pivoting mount frame. You can buy right H4 lamps from 928 Intl or 928 Specialists.
http://www.billsworkshop.com/P928S4/h5toh4/h5toh4.htm

jon928se

88 is still hydraulic, 90 is electric - not sure of precise changeover but with digidash models? same time as doolocks went to solenoid operated vs the older electric motor type

Bill Ball

Jon: I got H4 lamps from an 86 or 7 in Italy and it came with electric motors.

Note: If you buy the lamp housings you don't get the aluminum yoke and motor, but when I swapped with this fella in Europe who was going to federalize his car, he sent me everything.

jon928se

Bill

musta been changed on that particular car - front end collision maybe or perhaps the owner got fed up with the "air" non-adjustable ex hydraulic system. 88 is definitely non working hydraulic 90 definitely electric (which requires a slightly different yoke)

inokiyo

Mines an 88, can confirm it is hydraulic.
If it's hydraulic and you still want fix it to work, here7s a link with a simple explanation.
http://www.928.org.uk/mambo/content/view/68/43

Bill Ball

Hmmmm.. OK, wrong again!. Maybe it was an 89 (or 90). 89 is where the locks and dash changed over. But I gather from the first note that it doesn't show in the wiring diagrams until 90. I just confirmed that and found the same with the anuual service bulletins - it first shows in 90. Eh, I should delete my earlier posts. Sorry about that. I could have sworn they guy from Italy that gave me the system had an older car.

Still, if the car was federalized, it would have lost the H4s and you can't mount H5 lens housings in the H4 frames. So, no pivot. The system could not be restored unless the whole lamp housing and frame was changed back to H4. If it still has H4s, then perhaps it can be restored with the right fluid.

And I see I made another mistake. For some unknown reason I presumed this was a Euro car brought into the US. Hence all the federalization and H4 vs. H5 stuff. Argh.

Alan

Arian,
I have added this system to my US spec car. Its not a task for the timid - its a lot of work.

Are you saying you have the electric adjuster system? on an 88? are you sure ? I thought nobody was as insane as I am? If there is a pot there - you are certain its not a fader right?

If you really have a system I can tell you how the stock system is set up - aftermarket add ons may have been done some other way...

Alan

StratfordShark

Yes I read your account of the switch and was humbled!

Thanks to all replies for your deep knowledge of the 928. I made a dumb assumption that I have the pot based on:

- somewhere I got the idea that with hydraulics there was an adjuster on both sides of the cabin

- an even dumber assumption that because my aim **** was marked 0-1-2-3 this corresponded to the 3 postions on the electric pot (actually just 3 switched resistors) whereas the **** must be marked that way on the hydraulic adjuster to in order to correspond with load situations in handbook. Doh!

- I was puzzled that pot only showed up on MY 90 wiring diagram, but assumed that the wiring was for a US car (I'm in UK) and that the two markets had differences in when changes were intoduced. i forgot completely that US cars didn't have any adjuster, just the dummy 'stump'.

So now I have another - hopefully better informed - question.

The advice on 928.org.uk about recharging the hydraulic fluid says something like "it will be obvious how to dismantle the adjuster" (so as to pour fluid down the pipe) but to this poor guy it's not obvious! If you just pull up on the adjuster the **** doesn't come off, or at least I don't want to force it. Do you have to get at it by removing the carpet around the handbrake, hatch release and adjuster or can you take it apart without lifting the carpet?

Thanks for your advice,

Adrian

jon928se

Yes

The only vaguely succesful refills seem to have involved removing the whole system - it's all one piece from the control **** through to each headlight - need to remove wheels, wheel arch liners and headlights. And even those don't seem to have worked for long. I replaced the whole system with a new one (bought cheap at an Auto jumble) and it worked for about three weeks.

If you have to have adjustable headlights (you won't need it for a UK MoT - just remove the adjuster ****) the effort of redoing the hydraulic system would be better put to changing it to the electric system.

StratfordShark

Hi Jon,

Thanks for this, but it's depressing!

The advice on 928.org.uk made it sound like a simpler job to refill then it really is.

My S4 passed its MOT very recently, and that must have been with system not working but the **** in place.

My ulterior motive in getting the system working is that without the hydraulics the driver's side (RHD) headlight beam adjustment has to be screwed right to the stop for lights to be correctly aimed. This means that the cowl on the light on that side covers the 'tell-tale' light at top of headlight, and the cowl is pushed slightly out of shape which bothers me since I'm looking right behind it!

Regards,

Adrian

Vilhuer

When hydraulic version dies lamp goes to one extreme because of the spring which is pulling it. This limits aiming adjustment range a little. If you want to restore correct range, easiest option is to take out slave pistons from light assemblies and install home made adjustment rods in their place.

StratfordShark

This is tantalising!

Do you mean remove the existing ball end connectors between the (non-working) hydraulic mechanism and the base of the headlight? Forgive me but I'm not mechanically-minded (maybe unsuitable 928 owner!) but how do you prevent the spring from pulling on the headlight? The pistons themselves seem pretty inaccessible - needed long nose pliers just to pull the connector against the spring tension when I wanted to reconnect the headlights after removing them for another job!

Thanks for any further advice on this option - sounds like just what I need.

Adrian

Vilhuer

To get system back to center you need to force frame like silicon fluid does. One way to do it is to replace those pieces with long bolt. You need to make some mounting points for it. Bolt will allow adjustment to same positions original system did when it worked.