Speedo

[pgoldsmith]

Information that might be interesting to some of you.
Ever since owning my car I've experience problems with my speedo not working all the time. To cut a very long story short I took the instrument cluster out, cleaned the connectors on the looms that bring the signal back from the gearbox sensor and also disconnected and clean the connector just behind the rear offside wheel.
For a few months it was fine, then it stopped. So I checked the connector behind the rear wheel, disconnected and sprayed some WD40 in there and the speedo was fine but after a few days it stopped again.
I then decided I'd had enough and would cut the connector off and just solder the wires together - although I didnt really want to. It was whilst I was handling this connector that I noticed that one of the pins in the moulding was moving out of place only slightly but enough to drop continuity. I put the connector back together took it for a run then stopped and gently tugged the loom and speedo stopped, I used a small screwdriver and pushed the pin back up and the speedo worked!
So if any of you are having intermittent speedo problems you could first check this connector thoroughly before plodding on to disassemble the dash.

rgds,

Paul.

I have an intermittent speedo on my car, works about half the time. Can you explain exactly where and what this connector looks like so that I can locate it? I have had a look in the engine bay behind the offside wheel but all I could see was a connector that fed into a larger connector (6cm x 4cm ish) with nothing plugged into it.

Many thanks

James

[pgoldsmith]

If you look immediately behind the rear offside wheel you should see either three or four connectors. The connector closest to the rear wheel is the one that connects the sensor from the gearbox to the wiring loom that travels back to the instrument cluster. I say there should be 3 or 4 connectors although I think that early models may not have had a connector mounted there but perhaps ran either a continuous cable back to the cluster or had the connector mounted elsewhere (may be someone with more detailed knowledge would comment please?). I've found that sometimes just by disconnecting this and soaking with WD40 helps but also the pins on mine seem to be a bit loose which is suspect. I've since bypassed the connector as an experiment and used some flying leads and a bunch of those connector blocks you can squeeze on existing cable to make a piggy back connection.
I'm still not convinced it's this connector that's playing up, as since making this mod it's failed again!!! .

The other part to look at is the connector on the Instrument Cluster end. If you sit in the car pull out the vent (a two pence piece helps here!) on the rhs of the dash and peer in (with the door open it makes it easier) your see a connector that runs horizontal and one a bit further away closest to the windshield which is positioned vertically. The horizontal one contains the inputs from the speedo sensor, the vertical one is for the rev counter. Try gently wiggling the horizontal one and see if that helps.

As I say I still feel unconvinced that its at the connector end so I'm going to try to get at where the sensor enters the gearbox and check that the shielding is grounded correctly to the gearbox . I'm hoping that it's this that's causing my problem.