Speedo

Stoonly

Hi all, so I have an intermittent speedometer issue with my 1990 245, its stopped working for the most part but occasionally will come to life! I can sometimes make it work when I bang the fascia? I have cleaned the terminals on the plug sender on the diff so I don't think its that, it must be an electronic issue with speedometer in the cluster, what should I be looking for when I pull the dash cluster, I,m guessing a bad solder joint somewhere?

ramrod

Yes pull out the speedmeter assembly and verify there are no dry solder joints on the pcb

jamesinc

No dry solder joints and also check the odometer drive gears (removr the motor mount on the side of the odometer to access) are not missing any teeth.

Stoonly

Thanks Guys,

I do have some replacement gears but not sure that's what it is, as it can come to life and then run for a while, anyway I'll find out what it is one way or the other! thanks again!

ramrod

Is it the speedmeter or odometer that isn’t working?

They are independent

jamesinc

Oh lol I totally read it as odometer 😆 yeah if the odometer is only stopped when the speedo is dead, the odometer itself is fine.

It's worth checking the wiring near the sensor, which is attached to the back of the diff. Often it is perished, I've had that be the cause of speedo issues before

Forg

If smacking the dashboard has a definite effect then it’s not a wiring issue elsewhere, though.

Major Ledfoot

Check out https://cleanflametrap.com/speedoDiag.html

Note in particular the terminal tension on the 3-pin connector to the speedo.

Stoonly

Thanks Major Ledfoot, that's gold!