GM Truck Club Forum banner
1 - 4 of 4 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 · (Edited)
I have a 1997 Silverado 305 5spd 4x4, and the speedometer reads way off. At 55mph it reads about 70. The transmission is original, and it has the correct tire size. I have replaced the speed sensor, replaced the little motors in the Gauge cluster as well as swapping it out with known good ones but I still have the same issue. When I hook up my code reader and monitor the speed it shows to be accurate, does a one have any suggestions to fix it, people have suggested calibration tools, but they are kinda expensive for something I'm going to use once.

Edit: Forgot to mention when speeding up or slowing down the speedo doesn't move smoothly it just jerks up to the speed, or sometimes if I slow down really fast it just hangs there, I can't Remeber for sure but I believe it did it with the other clusters and Gauge motors.
 

·
Registered
2000 Silverado Z71 4x4 5.3L 460k+ miles w/ GM rebuilt motor and trans
Joined
·
1,424 Posts
So, if I read this correctly, based on GPS data and the code reader, the computer is getting the correct speed reading, but the gauges are showing the wrong thing...So there is something between the computer and the speedo telling the speedo it needs to do something else. I would examine the wiring, wiring harness, the connector pins, etc. all the way back to the computer. You may have a mostly severed wire inside the sheath which is only sending intermittent signals to the speedo.
 
1 - 4 of 4 Posts
Top