Sick Speedo

Ok guys, I've heard one or two of you saying that your speedo's don't work. Whats the answer? Mine won't work above 80mph (drops back to zero) and sometimes doesn'r register anything when I move off. Any idea's

First, check the battery earth connection.
Remove the battery, remove the battery tray, remove the earch lead, clean up and clean off all the rust.
Reassemble the earth lead and the terminal connections with a waterproof grease/rust-inhibitor, Vasaline is a good substitute.

see i that helps.
Mine was well rusted and it did improve things, but not completely.

[Alpineandy]

and get some spray electrical contacts cleaner.

After enduring an intermittently working speedo for ages I finally found a permanent fix, thanks to some advice from Andrew Jones at CAR.

You need to remove the top part of the dash, around the instrument binnacle to gain access to the multi plug connector, which plugs into the right hand side of the instruments.

This isn't as daunting as it might sound. You'll need to remove the steering wheel first, for which you need two M7 size bolts. Be careful not to snap off the fragile plstic screw hole lugs on the dash when you remove it. They're very fragile and if you snap any you'll have a rattly dash when you put it back and find you can put the screws back in!

Once you have access to the right hand multi plug, disconnect it. It has lots of small spade type connectors inside the plug. You need to use a very small jewellers type of screw driver or similar to push these connectors up tight into the plug, to make sure they make a good contact with the pins when you plug it back in.

The problem is, over time the spade connectors in the plug can become loose and no longer make a tight connection on the pins it plugs onto.

I found my speedo would work from cold. But after a few minutes, because it's electrical, once it warmed up my speedo would start to work erratically and then stop working completely.

Thanks to this information from Andrew, I tried it and my speedo worked perfectly ever since!

Must admit mine used to exhibit those symptoms until eventually it stopped completely one day, then no matter what fiddling I did a new head unit was the only answer (ouch !). Simon Autos were the most reasonable source of a new one back then... Since then no problems at all...

Tried the battery earth. had no luck so the dash came off this weekend, pushed and proded the conections, gave them a spray of WD40, put it all back together and took it for a teat run. Hey presto, it now works perfectly! Thanks for the advice