Weird odometer/trip meter problem
 

So my odometer and trip meter stopped working. I ordered the proper replacement cogwheel and replaced it myself. everything was working for about 300km's then it stopped... i opened it back up to see if something broke again but there was nothing out of the ordinary. I put everything back together and took it for a drive and it worked for not even one KM! ... took it apart again and still nothing out of the ordinary.. put it back together and took it for another drive and it seems to be going slower then it should be... i drove to the auto parts store which is 1.5km away so a total of approx 3km.. when i got home it was showing only 1.5km!...

any input would be appreciated !

thank you guys

I take it this is for your '86 740?

I'm not sure if these used electric speedometers or if they were still mechanically driven. If you want to try a new cluster I have a really nice one, dunno if it'll hook up 100% given that its from a turbo.

yea sorry forgot to mention its an 86' 740 automatic wagon

here is a pic of my exact cluster

http://www.davebarton.com/pic1.2.jpg

http://www.davebarton.com/pic1.3.jpg

Something electrical kike a capacitor or two acting up OR the circuit board...

When you replace the odometer gear, you need to check through all of the mechanics of the odometer to make sure none of the teeth that came off the old gear aren't stuck in there where they can jam and cause the odometer to stop. I'd go back and look for this as the potential cause of the problem. Also, check the solder joints on the little motor that turns the gears. Sometimes they develop cracks in the solder which causes it to run intermittently.

Apparently I have to do this job coming up shortly as my odometer has stopped working.

Thanks for the great information ..

unfortunately i took it apart again and even made sure for the fifth time that there was no old teeth in any part of the gears.

put it back together and still nothing.. and onto of that the speedometer stopped working today too !

I did read somewhere that in some cases the odometer takes time to reset and will eventually start working.

If the speedometer doesn't work, then it isn't related to the gear. I would check your connections as it may not be getting the signal from the differential.

In my previous post I had failed to notice that this is a 740. I know little about these as I have only owned 240s. I have read that the 740s do suffer from failing electrolytic capacitors as Lev noted. You might want to check those for any burst or bulging caps on the circuit board.

I am well aware that the speedometer has nothing to do with the odometer gear.

it just so happens that now the speedometer does not work ! :(