AU Series 1 Speedo

dgb · 07-05-2007, 06:32 PM

I have a AU Series 1 (1999) Auto and 6 cylinder, and the speedo occasionally 'hops' between 0 and 20ish km/h whilst at a standstill. I had a search on the forum, including in the 'common problems' thread, and there is one mention of a similar problem (amidst a general diatribe against the AU) but there didn't seem to be any follow-up or advice.

Does anyone know what causes this? Is it common? Is it indicative of a bigger problem or has an easy solution?

Casper · 07-05-2007, 06:33 PM

Its usually attributed to an earthing problem.. much like the oil pressure gauge issue.

mattp · 07-05-2007, 06:59 PM

Check this out...

http://www.fordforums.com.au/showthread.php?t=95045

Then this...

http://www.fordforums.com.au/showthread.php?t=98562

lostdude · 07-05-2007, 11:23 PM

i had a similar problem but mine also got stuck sometimes,
turned out the wiring at the back of the speedo was loose and eventually fell off and i had nothing for a while lol.

dgb · 08-05-2007, 10:23 AM

Thanks for your help.

dgb · 13-05-2007, 08:29 PM

A bit of an update is in order. The car was due its next service shortly after I wrote the first post (its just clocked up 200k) so I thought I'd wait till then as it isn't a serious problem and more an annoyance.

So whilst it was up on the ramps in the midst of its oil change etc. I pull the gearbox connectors and give them a good cleanup as per GK's post - scrape with a screwdriver and spray with some electrical cleaning spray, dislodging a surprising amount of dirt.

Go for a drive, and the box seems to shift more crisply and kickdown better, so I'm happy on that front. However, a little later on when stopped at traffic lights the original problem occurred again. So I guess I'll move on to the next of the possible causes, a dodgy earth.

Which of the earth(s) are prone to dodgy connections (especially ones relating to the gearbox/instrument cluster) that I should look at first or might overlook?