1989 moon gauge speedometer works for 5 minutes

[uhhhpooo]

(I think this is the spot to put this or if not in interior)
I have a 1989 c1500 it’s has a 700r4 trans, but my speedometer works for 5 minutes then quits but as soon as you shut off the truck and turn it back on it works for 5 minutes then shuts off, leaning towards a speed sensor that is at the tail of the transmission or a loose ground/bad ground, if y’all could give me some more options or help me figure this out it would be helpful.

 

[Schurkey]

The speedo on my '88 went intermittent. Not as regular as yours, mine worked or didn't work totally at random.

When my speedo quit, the cruise control quit, the ABS quit, the torque converter clutch disengaged, and the MIL lit up.

On mine, it was the circuitry in the instrument cluster. The speedo itself was good, as was the VSS in the transfer case.


A loose ground or a speed sensor wouldn't work good for five minutes and then die, time after time, predictably.

 

[uhhhpooo]

The speedo on my '88 went intermittent. Not as regular as yours, mine worked or didn't work totally at random.

When my speedo quit, the cruise control quit, the ABS quit, the torque converter clutch disengaged, and the MIL lit up.

On mine, it was the circuitry in the instrument cluster. The speedo itself was good, as was the VSS in the transfer case.


A loose ground or a speed sensor wouldn't work good for five minutes and then die, time after time, predictably.

oh, i don’t now about my cruise control since i don’t have it, my abs stills works and my torque converter is fine, other then it doesn’t want to kick down when the speedo isn’t working

 

[Leeztruk]

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