Speedo
Thread Starter
Heel & Toe
Joined: Dec 2011
Posts: 20
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Speedo
Can anyone tell me why my speedo is jumping around. It will start find from stop, but then if there is a mild bump in road, or even sometimes just falls to 0. Any advice may help. Are the pulses from speed sensor causing this I suppose?
Race Director
Joined: Oct 2004
Posts: 13,598
Likes: 1,353
From: Home of the VOLS ! Knoxville, TN. Tennessee
St. Jude Donor '11-'12-'13, '15, '16-'17-'18-'19
It may also be the cluster guage itself. GM is known to have bad stepper motors in their clusters, just haven't heard about it happening to C5s.
Stepper motors are about 5 bucks each if that's your problem, but you have to have soldering skills to replace them as well as the knowledge on how to take the cluster apart.
I would start with connections to the speed sensor and ground connections first though.
Also check and see if you have any codes showing up on the DIC.
Stepper motors are about 5 bucks each if that's your problem, but you have to have soldering skills to replace them as well as the knowledge on how to take the cluster apart.
I would start with connections to the speed sensor and ground connections first though.
Also check and see if you have any codes showing up on the DIC.
Race Director
Joined: Oct 2004
Posts: 13,598
Likes: 1,353
From: Home of the VOLS ! Knoxville, TN. Tennessee
St. Jude Donor '11-'12-'13, '15, '16-'17-'18-'19
Once you get the codes off the DIC (H=history, C=current), then check here to begin narrowing down the problem(s)...
Here is how you get the codes:
http://www.stengel.net/diccodes.htm
Here is how you get the codes:
http://www.stengel.net/diccodes.htm
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
It sounds like you have one the wire harness clips loose and you will need to try to see if that is the case - it is entirely possible too that you might have a loose ground as well -
But here is a tutorial on how to remove the Instrument cluster to get to the harnesses:
http://www.vetteessentials.com/instr...zel_howto.html
Thanks,Matt
But here is a tutorial on how to remove the Instrument cluster to get to the harnesses:
http://www.vetteessentials.com/instr...zel_howto.html
Thanks,Matt
Thread Starter
Heel & Toe
Joined: Dec 2011
Posts: 20
Likes: 0
Speedo
ok thanks...Where are the grounds? I know about the one on the driver side engine compartment. Im assuming that is the only onr? I am going crazy here, cause now the alternator isn't showing charge. I thought it was ground on that issue as well, but I only saw the ground in sight.
It sounds like you have one the wire harness clips loose and you will need to try to see if that is the case - it is entirely possible too that you might have a loose ground as well -
But here is a tutorial on how to remove the Instrument cluster to get to the harnesses:
http://www.vetteessentials.com/instr...zel_howto.html
Thanks,Matt
But here is a tutorial on how to remove the Instrument cluster to get to the harnesses:
http://www.vetteessentials.com/instr...zel_howto.html
Thanks,Matt
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
The alternator and battery come together at the starter solenoid. You might want to look there but do not forget that its electrically hot down there unless you pull the battery negative lead first.
