as the title states, I'm having an issue with my speedometer, and was wondering if anyone else has had a simple fix for the same thing... I'm prepared to replace it if need be, but hoping to avoid it if possible...

my speedometer works intermittently, and usually will read anywhere from 45mph (stays there if I'm over) to 90 mph (even if I'm doing around 30 mph) and other times it just sits at zero and twitches around... the odometer works fine, so I've pretty much ruled out the speed sensor and the power feed to the speedometer... does anyone know if it uses the same feed to work both, or does the speedometer feed work seperate of the odometer? electrical has never been my strong point as far as repairs go, so any suggestions would be appreciated...

Thanks,
Darin

 

I am not familiar with the 92 unit and don't know if the odometer is mechanical or electronic. On my 89 I had a twitching problem with the speedometer and after sorting it out I found a broken wire at the speed sensor in the differential. My odometer would turn but it was not accurate because of the wire problem. On my 89 the odometer is mechanically driven by the speedometer (small gear drive) so if the needle stops the odometer does not run. Also the sensor is in the rear differential in my 89 and it became corroded over time. I would inspect the sensor first and if OK then you will need to pull the instrumental panel and either fix or replace the speedo. Please keep us posted on what you find.

 

your speedo is electronic, u have diods inside going bad, u have to replace them or get a new(different) unit. a speedo shop can do it,

 

appreciate the responses guys, I'll check the wiring doing to the sensor for breaks/corrosion, and will spend less at the local junkyard than I would at a speedo shop(there's only one in town, and he knows it).

 

i have precisely the same issue with my 90 740ti. all the gauges work fine, just the speedo needle jumps and drops intermittently and constantly. when the needle falls, the trip and odo quit rolling as well, diagnostic told me no speedo signal. i puled the sensor and cleaned the terminals and pulled the instrument panel and checked all the connections. problem continues to persist. anyone know of a way to check the wiring from the dash to the sensor?