Speedo & Rev Meter - Intermittent failure....

[mattross]

My Rev meter & Speedo intermittently works, it either works perfectly, or not at all. All other gauge always work (fuel, temp etc). When they don't work, i have observed:
- When key turned to on the speedo sits on around 3km/hr
- When driving the speedo twitches
- Rev meter never moves

I have been told by 3 different people 3 different causes, confusing me, experts out there maybe you can help:
1. Impulse sender in gear box is gone (Volkswagen Golf III 2.0 > Drivetrain > Sensor > ES#2090989 Vehicle Speed Sensor - 1H0919149A)
2. Something in the back of the dash is gone (cluster?)
3. One of my ABS wheel sensors has failed and the speedo/computer drops it out, or the ABS system has a failure somewhere

Anyone know the real cause?

[rayray086]

It's a common problem (since they're getting quite old now) that Mk3 dash clusters start to fail. I had mine fail on me about half a year ago, and I thought it was the speed sensor on the gearbox that was gone (my speedo went first, then the tacho) so I replaced that first but I still had the problem. I ended up finding a second-hand cluster and changed it up and it works perfectly now.

I'm pretty sure you can eliminate the ABS problem, as it shouldn't have any relation to your speedo/tacho reading? I'm not sure about that one, but it just doesn't make sense to me that they're related.

Hopefully someone can provide instructions on how to test which one is actually not working?

[Golf Loon]

Dance of Death when the needle twitches. Its an internal fault with the chip in the cluster and is a known fault.
Only cure is a new or used cluster. Ks are stored on the cluster so try and match em up with something similar if iis a good car. New ones will have 0 ks on it.
I have new and used clusters here.

[mattross]

Wondering, if the gearbox impulse sensor detects the engine speed (revs), where does the speedo get its input from to determine the Velocity