another speedo

[slideordie]

doesnt work 2/3's of the time, occasionally it jumps up and down when i'm driving along and then works, then stops, then works, then stops etc ... replaced the speedo sensor in the back of the diff, didnt do any good. left it in to a spark this morning and he's just phoned to say that he thinks it the PCB in the instrument cluster.

replacing this was really a last ditch option for me as i will have to source the parts etc. basically i was looking for a simple fix here, like a damaged wire...

has anybody got any other ideas what it might be? i searched extensively before posting this but cant find any other info apart from replacing the sensor and checking the speedo wire running under the car.

also, if i do have to fit a new PCB will one from a 318i fit my 318iS?

Many thanks

UPDATE: spoke to a BMW specialist breakers and they have an iS cluster for Ԛ£60, says I will not be able to swap boards as it is too delicate...

[kam-325i]

I had a similar problem, it turned out to be dry joints on the soldered connections on the PCB, a quick flash with the soldering iron fix'd it.

[slideordie]

i suppose it wouldn't be a bad idea to take my cluster out and have a look.

[cheesebox]

Could also be tired batteries in the SI board in the instrument cluster...

[slideordie]

Could also be tired batteries in the SI board in the instrument cluster...

are these easy enough to spot? are they small watch-style batteries?

[kam-325i]

No, they are the same size as normal "AA" size batteries.

[slideordie]

ok thanks, will replace them and see if that fixes it

[Turbo-Brown]

I'd have thought that it just wouldn't work if it were dead batteries?

Mine was cured by re-soldering the joints.

I thought the batteries were about half the length of AA ones too.

[bigdek]

service indicator batteries are nothing to do with the speedo.

[E30Mark]

UPDATE: spoke to a BMW specialist breakers and they have an iS cluster for Ԛ£60, says I will not be able to swap boards as it is too delicate...

Hollocks! delicate my

I'm just doing a write up at the mo, had to take my clocks out last week to stop the brake lining lamp from flashing on and off all the time!

I have a complete set of pics of how to remove and dismantle if you need...

But to be honest it's not difficult to rip the dash part.

If you do go swapping parts around make sure you get 'motormec' bits for your car, as I'm sure the 318iS never had the VDO gauges.

You say you replaced the speed sensor in the the diff' did you check the cable for breaks? these are prone to breaking down and giving an intermittent speedo

[slideordie]

UPDATE: spoke to a BMW specialist breakers and they have an iS cluster for Ԛ£60, says I will not be able to swap boards as it is too delicate...

Hollocks! delicate my

I'm just doing a write up at the mo, had to take my clocks out last week to stop the brake lining lamp from flashing on and off all the time!

I have a complete set of pics of how to remove and dismantle if you need...

But to be honest it's not difficult to rip the dash part.

If you do go swapping parts around make sure you get 'motormec' bits for your car, as I'm sure the 318iS never had the VDO gauges.

You say you replaced the speed sensor in the the diff' did you check the cable for breaks? these are prone to breaking down and giving an intermittent speedo

what do you mean by "motormec"? sorry, i've just never heard of them..

yes i checked the cable myself as did the spark this morning, he said it was ok but replaced part of it as it enters the plastic connector anyway as he says they can sometimes corrode in there and you cant see it? he's a very well respected spark so i do trust him that its not the cable, unfortunately.

replacing the cluster is last ditch as i said, am remaining hopeful that checking the joints will cure it...

if i do have to replace the clocks i'd very much appreciate your pics and info E30Mark, thank you

[E30Mark]

The E30 clusters are made by two different manufacturers in the past. VDO is one, the other was Motormech (i think i've spelt it right...)

You can't interchange the VDO & motormech speedo's (as the odometer wont work)

You can safely swap the complete motormech cluster for a VDO cluster though.

PM me your email and I'll send the pics through as soon as i can, you got broadband???

[slideordie]

This motormec?

www.motormec.co.uk/

You got PM

[E30Mark]

Ooops i might have created some confusion here, sorry!

When i said motormech i meant motometer, they were a OEM (original equipment manufacturer) for BMW. It's the make of the cluster.

Nowt to do with www.motormec.co.uk/

No PM received...

[cheesebox]

Here's a useful site illustrating removal of instrument culster:

http://www.beckerelectronics.com/SIboard/siboard.html

[slideordie]

Ok i'm woth you now mark! PM sent now

thanks for the link cheesebox, very helpful

[Brianmoooore]

Non working/intermittant speedo problems on an E30 are caused either by an internal break in the wiring loom just away from the diff. or by dry joints on the cluster.
Nothing fragile or delicate about the cluster as long as you don't put the board needles down on the bench and use a bit of common sense.

[bigdek]

or in my case previous owner made a James Hunt of installing a head unit and it was blowing fuse 12 all the time stopping the speedo from working

[slideordie]

shall check the joints and fuse before i go and replace the clocks, thanks for the info folks