speedo help please

[swerve2007]

hi guys,
i need to have you throw some ideas my way please.

i had the gauge cluster and center console out while upgrading the stereo and fixing some wiring routing. everything worked when the car was parked 4 months ago. when i put it back together the speedo didn't work (everything else does- i rechecked the connections as well).
here are the questions:
-although it all looks good, are there components/wiring under the driver-side dash that could cause the speedo to fail?
-can VSS simply fail without warning? where exactly is it at in the engine comp?
-any ideas?

i appreciate your input, i am clueless on this one.

 

[Larry Bastanza]

Well, if it was me, I would be removing the gauge cluster to find out what I possibly did not connect or broke. I would be really hard pressed to think the VSS, located on the transmission, broke, because I had the interior apart.

Whenever something like this happens to me, I immediately accept the fact I broke it, and go find the issue. Sorry I do not have better news, but I give it less then a fraction of 1% probability it is the VSS.

I am only commenting based on my own personal experience. I call it the "Duh" factor. Been there, done that!

HTH,
LarryB

 

[swerve2007]

thx larry,
i did pull the cluster to check the connections- all looks ok.
is there a way to test the speedo gage itself?

 

[J-RnsxT]

check if theres conductivity on your VSS wire connections, your car sat for awhile and. My indicator were the spedo gauge going up and down as you drive, then few days later, it stayed on 0. Your engine light should be on right.

 

[swerve2007]

ok, checked all the connections and they look fine- i have to eliminate at least one unknown.

is it possible to verify the speedo operation with the cluster removed from the car? can a dealer or SOS do that? can I do that with a meter? anyone knows how?
thx

 

[spider2k]

if you know the exact wire for the VSS you can jack the car up and spin the wheels to see if it pulses with a meter. or if you have the room just roll the car forward 10-20 feet.

 

[drew]

Did you disassemble the cluster? If so, the big gold colored screws need to be firmly tight to make the proper connection on the circuit board.


A VOM might not work due to the time required (latency) in getting a reading.

You can use your computer sound output as a signal generator to simulate the VSS. The waveform and voltage range is gone over in detail in the shop manual, just duplicate it the best you can with the below tool

http://heliso.tripod.com/download/generator/dsg.htm

I suppose you could use the sound card input to view the VSS signal too.

Drew

 

[swerve2007]

thanks drew,
i'll check the screws and the vss.
btw, thats a great tool you found.

 

[swerve2007]

the mystery is solved- thanks for ideas.

i jacked the car up and checked the vss- it was good. i let the car idle in 1st gear which proved the odometer was working so the signal was reaching the cluster. upon dissasembly i found a barely visible crack in solder of the connector housing.

 

[Larry Bastanza]

Gald you have found it. Do you think this was a result of the removal of the cluster? Just fragile, maybe it got bumped or dropped?

I have done a few Carbon Fiber dash face plates and I am very careful with the cluster, I guess I have been pretty lucky.

Regards,
LarryB

 

[swerve2007]

hi larry,
i tried to be careful with the removal of the cluster but i did find the right side connector to be difficult to pull out. since the car was 'modified' by previous owners and i am returning it to stock condition, i think that the cluster was removed before so i just might have unknowingly aggrevated the issue. in any case, i would advise not to 'rock' the connector sideways if it does not come out easily.
btw, that was the most unpleasent waste of a week of time but now the interior is complete. now the front bumper......