tarakian

Ok been reading all the speedometer problem threads. Seems like a very normal problem.

Background
I have a 92 Camaro - RS - V6 - Auto. While driving all the gauges work on the cluster except the speedometer. From what I have been reading this typically is the cluster or the VSS.

Symptoms
While I am driving down the road, the ECU locks up the torque converter, but the speedometer doesn't work. After reading Haynes auto manual there appears to be another sensor on the back of the gauge cluster.

Question
From what I have read and how the speedometer is not working yet the VSS appears to be working, is it logical to assume the problem is in the cluster? Either with the plug in sensor on the back of the cluster or the actually speedometer itself. My main reason for thinking this is because the ECU is locking / unlocking the torque converter yet no speedometer functionality.

Just was wondering what you all thought before I tear appart my dash / console and everyone thinks its the VSS at the transmission or something like that is easier to check / double check before hand.

Thanks for any pointers in advance.

thirdgenlover

i myself dont know, like you said for it to lock up it needs a signal. so i would have to say that for some reason the cluster its working

Wadebryant

Two common areas that I've found to be problematic are;
1) The connection at the vss on the tail housing and
2) Loose wiring connection between the male pigtail and female receptacle on on the back side of the cluster.

You cannot visually test either one of these problem prone areas. However, a fault at either one of the above will cause the same problems that you are experiencing with the speedo.

Make sure that your connections are good. That may include getting under the vehicle and disconnecting the vss wiring and test for loop continuity back to the ecm with an ohm meter. One side will show a closed loop and the other should show resistance. Check across your vss to ensure it's not open. Make sure the female ends of the wiring are good, crimp them slightly and make sure the connection is solid. I even tie wrap it tightly. Then, go topside.
Disconnect the battery. Pull the ecm. Pull the connectors on the ecm and find the yellow and purple wire that go to your vss. Use your ohm meter and test for a closed / completed circuit. If okay, reinstall the ecm, reconnect your battery and test drive. If the speedo still does not function, pull the panel under the steering column. Find the wiring loom that goes into the back of the cluster and gently push them into the dash toward the cluster (these are secured to the dash so be carefull). Again, test drive. You may need to repeat this step. Hopefully one of these two suggestions will help you fix the problem. If it persists, or you need additional help...just ask.

BigBadLou

iTrader: (3)

Also, a bad ground at the speedometer connector will render it inoperative. Fixed the same problem on my buddy's Z28.

You can also check for signal on the grey wire on the connector behind the speedometer. If there is no signal with wheels spinning, you have a problem in the wiring. If there is signal, the cluster has a problem (fuse, ground, broken).

Hope this helps.
Lou

tarakian

Thanks for all the pointers, printing them out now. I will try to check these things tonight and let you all know what I find out.

freeyasoul03

i tryed to put the targo switch in to disconect the speed sensor but it did work any suggestions? will try another switch first

tarakian

Well after taking the cluster out, mine doesn't look at all like the one in the Haynes manual. Anyone have this cluster and been able to test the speedometer while it is out of the car? The speedometer doesn't move at all when the cars ignition is turned off and on.

BigBadLou

iTrader: (3)

That is a standard 91-92 instrument cluster. What does your Haynes show? Maybe the old full-circle gauges?

Lou

tarakian

It shows some other models. Anyone have a wiring diagram for this to "manually" test the speedometer while its out of the car. Or to test the connections in the wiring harness pictured? I would like to manually test the cluster to make sure the speedometer is working.