Speedo/tach failure...HELP!

[uncle-boris]

The speedometer and tachometer on my '96 passat have stopped working and are pinned against their upper limits. My wife was driving when it happened, so I don't know exact conditions when it occurred, but I have no reason to suspect foul play or pilot error... extreme cold the only unusual factor I can think of offhand, and I can't think of a way to connect that. I can hear a slight spinning/scraping sound in the dash, tach related, and the tach does come down very slightly from pinned if I rev and decelerate the engine. Anyone have experience with this, or suggestions?

 

[RIP TDI]

Passat intrument clusters are very vulnerable to damamge from low voltage, like when you try to start your car in cold weather with a weak battery. Usually, the first symptoms are the clock and trip odometer resetting themselves under the conditions described above, but the servo motors that drive all gauges are controlled by the cluster's chip and both can be damaged by low voltage.

If your battery is in any way questionable (especially at this time of year), replace it before you remedy your cluster problems or you will re-damage the replacement cluster.

These clusters are not rebuildable by speedo shops and your options are factory rebuilt from the dealer or finding one from a wrecking yard. Despite the higher cost, I would recommend a factory-rebuilt as it will have a warranty. Dealer-supplied clusters are orderable with your present odometer mileage pre-programmed (it cannot be done by the dealer or a VAG-COM and comes from the rebuilder with a reading of "00000"), but dealer parts departments don't know this fact, so if you go this route, you will have to be pro-active and educate them.

 

[GoFaster]

Actually, the Passat clusters ARE rebuildable! I know this, because I have just had mine rebuilt for the second time. THIS time, the shop that did it has identified the problem (fragile power supply on the circuit board) and has replaced that with a different power supply so that "it shouldn't ever happen again". So far, so good. This morning's start was at -22 C or maybe a bit colder, and there were no ill effects.

I asked the dealer that sent it out for me if this particular speedometer shop wanted more business (i.e. see above), but apparently they've got all they can handle from the local area and cannot take on any out-of-town work.

 

[uncle-boris]

Oh, man! I was kinda hoping for something cheap 'n' easy... this is sounding a lot like neither! I haven't had a chance to check prices yet, but I'm guessing a new (rebuilt) cluster, or a rebuild of mine IF I could find a shop capable, would be spendy either way, and prob'ly no picnic swapping it out. Bummer! I guess the next question is: Will I do further damage if I continue to drive the car while I hunt down parts, etc.?
Thanks for the prompt and concise info. This is a great resource, and I DO appreciate the help, even if it wasn't what I wanted to hear!

 

[RIP TDI]

Originally posted by GoFaster:
Actually, the Passat clusters ARE rebuildable! ... I asked the dealer that sent it out for me if this particular speedometer shop wanted more business (i.e. see above), but apparently they've got all they can handle from the local area and cannot take on any out-of-town work.

<font size="2" face="Verdana, Helvetica, sans-serif">This is a rare shop, indeed. When I was researching putting a GLX cluster in a TDI, I contacted virtually all of the major Southern California speedo shops and all of the major speedo shops with a web presence, nationwide (U.S.), who claimed the ability to handle late model electronic Euro clusters and none of them were able to rebuild the Passat's MotoMeter.

Uncle Boris, your cluster is already toast...you won't make it irreplaceable or unfixable by continuing to drive it. And R & R-ing the cluster is quite easy.

[ January 28, 2003, 08:41: Message edited by: Chris Bell ]

 

[ecd1vw]

Well my Instrument Cluster just fritzed out this morning. The speedometer starts at 30 mph -- so everything is screwy. The first signs were yesterday when the speedometer moved in small jumps -- not a fluid/smooth motion.

So, now I must start figuring out a solution.

/erik

 

[uncle-boris]

A couple of short drives and mine crapped out entirely: temp and fuel guages, clock, odometer, and the speed and tach went to zero. Clock and odometer came back the next time I drove it, but nothing else. Looks like 400 smackers to have the stealership install a rebuilt... ouch! I haven't done the math, but I think I'd have to be getting about 1400 miles to the gallon to break even on this car!