86 speedometer not working
Thread Starter
Advanced
Joined: Aug 2014
Posts: 56
Likes: 1
86 speedometer not working
I have an 86 that i'm putting back together after someone abused her for years. I have finished almost everything and now am down to only 2 problems. The first is the ABS which thanks to everyone here I found one of the relays to be bad. The second is the speedometer does not work. I drove it the other night with my scanner hooked up and it reads vehicle speed. With that I know the VSS is functioning properly. The rest of the gauges and tach work properly also. What next?
Racer
Joined: Sep 2014
Posts: 429
Likes: 29
From: Brooklyn, MI
I have an 86 that i'm putting back together after someone abused her for years. I have finished almost everything and now am down to only 2 problems. The first is the ABS which thanks to everyone here I found one of the relays to be bad. The second is the speedometer does not work. I drove it the other night with my scanner hooked up and it reads vehicle speed. With that I know the VSS is functioning properly. The rest of the gauges and tach work properly also. What next?
Racer
Joined: Sep 2014
Posts: 429
Likes: 29
From: Brooklyn, MI
Sounds like the display is broken. The dash does a self test when power applied. All graphs go full scale and digital readouts go to 88.
Pro
Joined: Jan 2003
Posts: 706
Likes: 47
From: Denver Colorado
Panel Repair
If the speedo is broken and the problem is not just a bad connection at the instrument panel plug in, try these guys for a repair: BATEE.COM. They have a very good rep.
You could also try cleaning the connectors where the panel plugs into the wiring harness with tuner or electrical contact cleaner (carefully... don't get it into the displays).
You could also try cleaning the connectors where the panel plugs into the wiring harness with tuner or electrical contact cleaner (carefully... don't get it into the displays).
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The VSS signal goes to the dash and gets shaped into a square wave and divided by two and then is sent to the ECM. If the ECM reads speed on the scanner then all that is OK.
Your problem is internal to the dash. The microcontroller is what makes the display work. There are also some connectors that are involved. Sending it to Bryan is probably your best option:
http://www.batee.com/corvette/dcrg/s.../iprepair.html
Your problem is internal to the dash. The microcontroller is what makes the display work. There are also some connectors that are involved. Sending it to Bryan is probably your best option:
http://www.batee.com/corvette/dcrg/s.../iprepair.html
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Racer
Joined: Sep 2014
Posts: 429
Likes: 29
From: Brooklyn, MI
The VSS signal goes to the dash and gets shaped into a square wave and divided by two and then is sent to the ECM. If the ECM reads speed on the scanner then all that is OK.
Your problem is internal to the dash. The microcontroller is what makes the display work. There are also some connectors that are involved. Sending it to Bryan is probably your best option:
http://www.batee.com/corvette/dcrg/s.../iprepair.html
Your problem is internal to the dash. The microcontroller is what makes the display work. There are also some connectors that are involved. Sending it to Bryan is probably your best option:
http://www.batee.com/corvette/dcrg/s.../iprepair.html
Racer
Joined: Sep 2014
Posts: 429
Likes: 29
From: Brooklyn, MI
The speedisplay is broken as you discribed earlier. There are three seperate displays in the dash. The speed, fuel/inst and the tach.