OTR18WHEELER

A follow up thread to my "low mile 928 thread" thread.
...so during the replacement of the failed odometer gear, I found a burnt resister.
As fate has it, the next day a matching inst cluster showed up on ebay, well..., I won the auction, today I had time to change out the speedometer.
The R&R went quicker this time.
All said and done, my speedometer WORKS!
Yay!, another notch in the 928 headboard.




So I got it all put back together, and everything works!
Another 928 WIN.




85 auto speedometer circuit board



85 speedo resistor board

beran earms

congrats. I still need to get into mine, but I need to get up the gumption to do so. Lots of finicky little pieces it looks like, I can picture my lap covered in bits of broken plastic.

MjRocket

That does look a little intimidating...Great Job Farris!


I might need to send mine your way for a little R&R.

UpFixenDerPorsche

All this humour is getting a bit frivolous don't you think Oits?

OTR18WHEELER

No, just documenting 928 common issues that I can use to add to my post count.

Hilton

I find this thread unfulfilling...

Does the non-working odo work after you replace the resistor??

I demand closure

Also, I'd be replacing those electrolytic caps while you've got it apart.. they're likely getting close to end of life (based on experience with failure rates in 70's hifi gear).

OTR18WHEELER

I bought the ebay unit for parts, hoping that the odo circuit board was good.
Since all my other gauges worked properly, I retained my original cluster.
After replacing the gear and adjusting the miles to show what is now closer to what The mileage should be, I separated the two halves, and only replaced the portion housing the speedometer mechanism and circuitry.
The speedometer is accurate comparing speeds with my GPS which is also accurate with those road side radar speed signs.
I have read other posts where some have been trying to diagnose non working speedometers, checking everything between the pickup sensor to the gear, I don't recall anyone documenting this type of fail with The speedometer unit.
So in closing, this thread is meant for educational purposes, and not just a frivolous opportunity to increase my post count.
Thanks.