service lights

[Rich320I]

slight random problem,

iv had a search through the wiki and cant spot anything so abit of info would be really great,

basically the service lights on my car keep flashing, all green about ten times then the oil service light goes off. then the whole flashing sequence starts again?

Any ideas?

[Speedtouch]

It's probably a sign that the Ni-Cd batteries are in need of replacement, but try resetting the lights first, using either the proper tool or a wire to short the diagnostic socket terminals.

http://www.e30zone.net/e30zonewiki/inde ... ion_Lights

[Rich320I]

cheers speedtouch, thing is i reset them then they where fine and then this morning they did that random flashing sequence,

il try reseting them again before replacing the batts. thanks for the help

[bmwowner]

how do you do the wire trick please speedtouch? I done a oil change, plugs and filters on sunday but lights havent been reset the last twice i have done it now. Thanks in advance. Dan. P.s sorry to jump in on your post Rich.

[Rich320I]

no worries mate i can tell you how to do the service light reset,

identify pin 7 on the diagnostic plug, ignition off attach pin 7 to ground/earth give it 15secs iginition back on and should be reset, same for the oil service indicator aswell,

[Speedtouch]

Another SI reset link:

http://www.noren.com/bmw/e30reset.htm

[bmwowner]

Rich thank you very much mate. Sorry i cant help with your car. Cheers Dan.

[daimlerman]

Sounds like the SI circuit board has gone tits up to me....
Do your rev counter and temp gauge play up as well?

[Rich320I]

nope rev counter is fine,
the temp gauge is on the blink though, im going to take the clocks out the weekend see if its just the nuts on the back?!

failing that though like you say il replace the batteries, iv not had the car long wierd how its suddenly thrown up this issue, old cars eh

[daimlerman]

The ni-cad batteries are the prime suspect,they tend to leak over the main circuit board when they fail,rendering that board difficult to repair.

SI board exchanges information with the others,so this can make tacho and temp gauge play up.

[Rich320I]

cheers daimlerman thats really helpful,

do you reckon its easier just to find a set of working clocks and swap them over then?

il take them out the weekend first just to make sure it is that first,

[Speedtouch]

It may be easier to replace the whole instruments, although it's fairly easy to remove the SI board and replace the batteries if they haven't leaked too badly.

[daimlerman]

cheers daimlerman thats really helpful,

do you reckon its easier just to find a set of working clocks and swap them over then?

il take them out the weekend first just to make sure it is that first,

That's certainly the 'easy' fix,but supplies of sound clusters are getting limited so you may have to strip your cluster and let some-one like a TV/computer repair place have a look.For them,it's something different and a bit of a challenge!

[Speedtouch]

The hardest part usually is finding replacement batteries with solder tags, and there are two different types - earlier SI boards had the AA type, while later ones had a shorter, Lithium type.

They are available on E-bay, and at the likes of Maplin:
http://www.ebay.co.uk/sch/i.html?_kw=aa ... older+tags

Alternatively, it is possible to carefully remove the solder tags from the original batteries and resolder them onto normal AA Ni-Cds.

[Brianmoooore]

It's not the failure of the NiCd batteries as such that causes problems, but the fact that these type of batteries tend to go short circuit when they fail. This presents a heavy load on the power feed to the tacho. and temp. gauge, dragging down the voltage, and making them fail.
No problem in getting suitable, if not absolutely direct replacement, batteries either. CPC and RS Components have plenty.
Even if fitting a complete replacement cluster, it's still advisable to identify which type of batteries it has, and to replace them as a matter of course if they are the NiCd type. At the same time, check the small filament bulbs on the LED display panel, the soldering of the joints of the large 220 ohm resistor, the soldering on the speedo. contact pins and the tightness of the two small brass nuts on the back of the case.
If the SI board has lithium batteries, the unlikely failure of these causes no other problems other than the loss of SI board memory if the car battery is disconnected.

[Rich320I]

thanks for all the information chaps, really helpful im going to take the cluster out on saturday and have a look whats happened,

cheers once again for the info very much appreciated

[Tenderfoot]

Sorry if I should have started a new thread, but as it's on the same subject....
Is it ok to start the engine with the cluster disconnected? I'm sorting out a SI problem too, and It'd be nice to move the car under cover.

[Speedtouch]

Yes, there shouldn't be a problem doing this.

[Tenderfoot]

Thanks for the quick reply...I'll give it a go.

[Grrrmachine]

Can I get confirmation that failure of Lithium batteries should not affect the temp gauge?

I've got a dead temp gauge and non-resettable service lights, and the temp gauge doesn't respond when I earth pin 4 of C101. The cluster is now out of the car, the brass night was fully tightened and upon disassembly I can see that I've got 3.0V lithium batteries fitted with no sign of leakage.

If it's not the batteries, I've no idea why the temp gauge doesn't work. Batteries reading 2.93V.

[Speedtouch]

Only one way to find out - try temporarily unsoldering one end of the batteries to remove them from the equation.

[Grrrmachine]

Yep, that answered that one. Snipped off the positive terminals, plugged the gauges back in and got a working temp gauge (which leaped to red after shorting the C101 pin).

Make a note, Brian; Lithium batteries can fail as well!

Also, does anyone know what type of "small filament bulb" is used for the Inspection, Oil and Clock lights? One of mine's blown.

[Brianmoooore]

Make a note, Brian; Lithium batteries can fail as well!

Duly noted!
What readings do you get from the disconnected batteries? Do they produce any voltage at all?

Bulbs are small wire ended 12 volt ones. I think the ones I use are CPC SC00339.

[Grrrmachine]

I got 2.93V across the pair of batteries, so they were in pretty bad condition. The new ones were at 3.25V each unfitted, and once installed the temp gauge started working again, so it's pretty conclusive.