SLS working - no laughing please

[Bruce]

so let me sum up the last few days of my SLS time...
I really wonder if I am getting old and decrepid or losing my mind or just this life of not working is getting me drunk too often and I cant focus on things properly. haha I dont know, but I made a few errors that are totally unlike me.

The car is fine when unloaded. with weight in it, it would sink, then pump up, click the pump off, wait a few secs then drop an inch.. wait them pump up, wait then drop and continue forever.
I suspect that the switch is the problem mostly because there is nothing else adjustable. I think dirty contacts are slow to open and close causing the over pumping and over dropping action..

SO I take the switch apart only to discover that there are no switches in side and there is a moving arc brush thing inside that rubs on a variable resistor trace thing.. sorta like our AFM.. so no dirty contacts or anyting to adjust ... some mercury switches and a circuit board. To get the switch apart there are five wires individually plugged onto the baord.

the 5 wires are:
accesory power
ground
up signal - output
down signal - output
and brake signal - input

anyway I cleaned it up and reinstalled it.... and the system was absolutely dead.... so now i am really convinced the switch is the problem ONLY TO FIND OUT THE SWITCH COSTS OVER ONE THOUSAND DOLLARS!!!!!!!!!

after fainting. I took it apart again.. then I discover my mistake - I plugged the power and ground in backwards. and it smelled like burned electronics inside. I cant believe I did such a stupid thing on a 1000 dollar part.
much close inspection and so on and I find a burned trace on the PC Board and fixed that. - I re-tested and found it will go up but not down. Back apart again and I find that under a diode there was another burned trace. so out with the diode and fix that and then finally the thing works again.

During all this I somehow put the soldering gun down and when I piced it up, it came with my mouse attached.. I melted the thing into the mouse.. aaaaaarrrrrrrggggggggghhhhhh.

Anyway so at that point I decided to go meet a friend for a beer and stop the work.

tomorrow I need to put the whole thing back together and somehow adjust the level.

I do notice that at different heights the shocks have differnet stiffness.. I wonder what is the right height???

Bruce

[Philo]

Man..., I would have given up and paid the 1500 for the new part !! You replaced diodes ? How the heck does one do that ! I know S*** about electronics.

I have a Service Information (SI) notice that BMW put out years back.., the previous owner of Armondo's car sent it to me..., can't recall his name right now, super nice guy.., anyway, the notice has the proceedure for testing and setting the system up after service is performed. I recall them saying that you need to put 800lbs in the car on a level surface and then pump the SLS up and set the ride height. Dinan also recommends (if you have their spings like me)the rear to be placed 5/8th of an inch higher measured at the door sill base forward of the driver's door and aft of the rear door. Personally I set mine to waht looks good to me.

I'll look for the SI for ya ! May take me a day.

Philo.
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[Bruce]

be set according to factory.... I see that with the trunk empty.. the car wont even go down to a reasonable level with the pressure drained. The 800 pounds makes some sense.. but where do i get that? certainly a lot of potatoes..

Bruce

[Todd Frye]

Although there has been lots of debate about saving OEM SLS in our rides, both Bruce and Philo are sharing some pretty valuable info here. Any time you guys wade into a procedure (i.e. r&r starter, shift linkage bushings, inop power locks, seat heaters, SLS, etc., etc., etc.) and if you're feeling generous, a step by step with photos would be a great resource for the rest of us who prefer doing our own work. My .02. Thanks to all those who share their knowledge so willingly. Todd Frye