• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

HUD Speedometer

jacobmh27

jacobmh27

New member
Tried Searching many of the Sub Forums but could not find anything. My Speedometer in the cluster is working fine. But my HUD is all over the place just scrolling diferent Number all the way from 0 to 199. Scrolling very fast. Scolling even at Stop with Car in Drive. Any Ideas??
 


From a corvette forum,thought it might help.................That sounds familiar. Didn't happen on my Vette, but did on a GTP I owned, while driving through Louisville. At first I though I had been driving too long, or I was experiencing a brain aneurysm. However, when I got home to TN, I pulled up the wiring schematics, and the schematics for this particular vehicle displayed that only two things could cause this were the power feed to the HUD or the ground.
However, the HUD on a Vette receives all its information from the DIC; whereas on the GTP the signals are received directly from the displayed systems.
Damn, I should read the entire post before making these long answers. You did say your cluster display was also acting erratic.
If only your HUD speed and I/P Cluster speedometer were acting flaky go to the following steps. If your entire gage clusters including lights, oil, fuel, etc. were acting flaky go to the ground check.
- Check the vehicle speed sensor connector (Yellow and Purple wires), located on the Top RH side of the differential. (If you have an ohmmeter, you can check the resistance in these wires from the PCM to the sensor and have someone wiggle the wires and the sensor connector to see if there is any sign of an open circuit)
- Also check the Dark Green/White wire on terminal 50 (this is the speed signal from the PCM to the cluster).
From here on in, it gets pretty tricky. You will have to pull the cluster and check the connector and wires at the cluster connector.
It could also be the speed sensor itself is going out.

Now, if all the lights and gages were flaking out, I would assume a ground was at fault. However, if confined to just the speedometer and HUD, then it sounds like a bad wire, sensor, or even a DIC.)
Check the ground in the Instrument panel harness, that is located below the battery tray, on the RH frame rail. Make sure the ground is not rusted over, and is clean, and the connection if very tight.
If this is ok, check the wire at the terminal to make sure it is not broken on the terminal stud connector. If that is ok, you can check the splice pack, located in the Instrument panel harness, on the RH side of Instrument panel. This ground splice pack is connected to the ground mentioned above.
If you need any procedures or further information, write me at [email protected].
 
Everything in the entire car is working propperly other than the HUD Speed the other lights in the HUD are off for the Gas and what ever other indications are there. The speed is just going crazy. Now a while back it started to act up mabey 6 Months ago. Not like now but when I would slow down it seemed to get stuck and then the numbers would quickly go down to 0. Now you can not use it at all the numbers are just all over the place.
 
I've noticed mine on my 00 GT when I'm around 25mph will once and a while go to zero and then back up to 25 really fast but then it will be fine again. Never really thought much of it.
 
seems like bafore this when I came to a stop after I became stopped it would count to 0 really fast from like 15 to 0
 


yesterday when I got in the car after work and the Car was cold it workied ok for a bit Seems like till the car got warma dn then went crazy again???
 
if its workig when cold i would say intremitte connection. Check the VSS wire , could be bad. if you try and dmm it might read well, replace cable all toegther
 
Could be a bad resistor on the HUD board or it could be a bad vss sensor. Could be a bad spot in the a wire somewhere too. Typically the speedo would do the same thing and bounce around if its a vss issue. Vss is the wheel bearing which is why I asked if there was an abs light. There's also one in the diff cover.
 


the speedo in the dash has no problems. I will remove HUD and check all wire tomorrow. And the ABS light is not On
 
You must log in or register to reply here.
Back
Top