Hello all if any of you on here have a 406 with a speedo not working this might help you.

My speedo would sometimes work but not until i hit about 50 mph (very anoying in a 30 zone) so i looked into it had diagnostics done on it and it came back with speedo drive fault. I have had the speedo out to fit new bulbs and discoverd i had no speedo cable on the speedo, so speedo drive fault did not make sence to me. so i trawled the interweb and discoverd people writing about a speedo interface box behind the glove box,somthing that not all 406's have.

anyway i checked my car and found the box behind the glovebox as described(a black box that will fit in the palm of your hand with a cream bezel or surround around the plug socket) any way i removed this box and drove the car for a week wiyhout it and the speedo did not even flicker like it used to so i knew i had the offending part.

next thing i did was to travel to all the breakers yards in a 25 radius of where i liveand could not pick one up at all, this tells me either they are very rare or have already been aquired by someone else.

after having no joy i resorted to ebay and picked on up for 20 quid, fitted it and the speedo worked until i switched the car of then it did not work again ,i sent it back for a refund (seller told me it was tested so i asked him what it does and he had no idea so how could he possibly have tested it if he dont know what it operates LIAR LIAR LIAR)

next step was to get my old one out of the bin and open the baby up,a tricky operation but doable, next was to wrap the plastic part in tin foil two layers. next was to take a heat gun to it the kind used for paint stripping held it about 4 inches away and heat the side that DOES NOT have all the resistors and wotnot on it making sure not to keep it blowing in one place. only do this for around 2 min's then i let it cool and slid the bad boy back together and refit it . MY SPEEDO IS NOW WORKING FINE AND HAS DONE FOR ALMOST A YEAR. you might ask what gave me the idea to heat it up,and it because people use this tecnique to repair xbox 360 and playstation 3 after they overheat and die .the aim is to reflow the solder so that it runs back inti the joints making a good connection again.

Its up to you if you try my fix it worked for me and if yours is bust it's bust so what have you got to lose.

if you need help you can message me hopkinsd@hotmail.co.uk

Edited by hopkinsd on 03/02/2011 at 18:45