check control issues

[Deftones 0]

Hi people

I recently purchased a second hand rear view mirror with maplights for my E-30.

With some instructions i pulled off the net Click Here , and tips from El-Gusto, I used the wiring loom from the check control. I split the brown wire (earth) and connected the earth from the maplight to it (soldiered). I then split the violet/green cable and soldiered to my positive for my maplights so that the circuit is switched/accessories.

Once connected back together, the check control and maplights didn't work when key was switched on.

I then used my multimeter to check for juice. Nothing. Decided to put it back together how i found it, connecting the check control wires back to each other, and the check control still didn't work. Checked the fuse and that was fine. Radio is connected to the same fuse and that was fine (checked all fuses). Even pulled the fuse out to test, and radio cut when pulled out.

Again I tested the cables with my multimeter, and still no juice.

Anyone have any ideas on what to try next? or where the wiring loom's next point is before the check control?

Kinda weird as everything was put back to how it was.

Thanks in advance guys and girls.

[Gus 5]

did you unplug the check control panel? is it plugged back in right?

tis v strange though

[Deftones 0]

Yup, unplugged, then replugged it back in. There seemed to be no juice at the wires anyway. My mate and I went over it a few times, but couldn't work out what was wrong. I'm not an autoelectrician by any stretch of the imagination, but I know my colours, and what to do and what not to do.

Weird science.

[jochen 4]

Look for...

Dirty, corroded, loose pins in the check control connector. Maybe the action of unplugging and replugging caused a bad contact on a pin to finally fail.

Eyeball the connector - if all is clean and shiny then should be OK

Get the wiring diagram (google for it) and see where the wires go.

Brown will definitely be earth - that's standard.

You sure you didn't break the violet/green cable?

Try

a) switching on the ignition and measure from Violet /Green to some other chassis earth point in the car. If you have power, then your brown earth wire is not connected to earth

switch off the ignition and measure ohms from the brown wire to some chassis earth point. Depending on how well you hold the voltmeter probes to the earth, you should measure less than 5 ohms. A good earth contact and you'd expect to see less than 1 ohm.

If you have no earth, then the brown wire is broken/unplugged from earth somewhere.

Jochen

[jochen 4]

There's a full E30 wiring diagram in PDF on the 'net

Get it here:

http://www.eserviceinfo.com/downloadsm/19876/BMW_e30.html

Interestingly, it's all in Russian :-) but the wire colours are in German

Looks like devide A1 with connector X27 is the Check Control Unit

See page 23 of the PDF file.

Pin 23 Violet Green is the permanent power, fed by Fuse 6

Pin 25 is the ignition switched power, also fed by Fuse 6

Use the diagram to help you

Jochen

[Deftones 0]

Thanks Jochen,

I will give it a blast this weekend (it is freezing and wet outside!).

Should I be able to measure some form of action if it isn't plugged in? ie. The check control is unplugged, and where I split the brown and green/violet wires I tested. Or does it need to be plugged in to test for a charge?

[petone 0]

but I know my colours, and what to do and what not to do.

like where to drill to mount a fire extinguisher?

Sorry, couldn't resist.

[Deftones 0]

haha.. Mike ya prick :P hehe

I just drilled where Carl told me to.. doh!

[Hartage 0]

Hahahaha,

When i drilled for my first fire extinguisher, i went through the fuel lines! ! !

[TronSpec 0]

Hahahaha,

When i drilled for my first fire extinguisher, i went through the fuel lines! ! !

Dats some funny shet

Please use correct English --> That's some funny sh*t

Edited May 16, 2006 by Carl

[jochen 4]

Hi Deftones,

You can unplug your check meter and then test your lights without the meter fitted.

The violet wire is +12V power

The brown wire is ground

You don't need the check meter plugged in for that to work

Jochen

[bumpstop325 0]

Personally, i would not have used that wire.

I would have used the Power for the sunroof.(cant remember if you have one or which type you have). As this a thicker guage and can handle more current.

This aswell, is unsuitable for componets that draw constant voltage. As when the sunroof is operated, voltage and current change. Due to the nature of its orginal design.

Looking at my spare loom, personaly the wire looks too small to support both the check panel and the lights. Keeping in mind, the lights are not always on and are seldom used. Was looking with electrial safety hat on.

[jochen 4]

Yeah but lets be realistic.

A small lamp with be 5W, maybe if he fits 2 it will be 10W

Thats 0.83A for 10W, and 0.41A for 5W.

Stuff all.

The wire is a 0.5mm2 wire, that can handle a piddly little bulb without too much trouble.

The checkcontrol will have its own on-board voltage regulator, dropping and stabilising the supply to 5V or 8V.

So fluctuations on the main line won't make much difference.

Jochen

[Hartage 0]

hmmmm

put the plug back in the check control and it works again!

:beer: :beer: :beer: :beer:

thats one you owe me Tane