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instrument cluster

2K views 2 replies 3 participants last post by  bobterry99 
#1 ·
[:(]
I may have posted my questions in the wrong site, sorry..
Inst cluster: Was able to remove,now at night the cluster doesn't light up. Fuses look OK, any advice.?
Also, gauges jump when I use turn signal, or sometimes when I brake. In reading through previous messages someone suggested re-soldering. Can someone provide more detailed info to fix jumping gauges.?
Thanks from sunny Pennsylvania..
[:)]
 
#2 ·
Did you ever get an answer to your question or figure out what to do?

I have problems with my instrument cluster on my 1990 500SL. It was rebodied as an AMG, and as part of the upgrades the prior owner added a new instrument cluster which is the AMG sport look with the ligter-background gauges. My speedometer however is not working - it jumps as soon as I start driving and oscillates back and forth between 60 and 80 no matter what speed I drive. Also the accelerator gauge maxes out and occasionally will fall to zero, and then go back to max. Like some other posting on this forum, I too have the problem with the warning lights on the instrument cluster all suddenly lighting up when I use the indicator, but only intermittently. I am wondering if there may be a problem with each gauge, or maybe some problem with the wiring harness. I have checked the signal coming from the trans going to the speedometer and it appears to be OK, so the problem seems to be more likely in the instrument cluster.

I was told first that I could have the gauge repaired, but then I was told the opposite, that the gauge cannot be repaired because the 1990 instrument cluster is all digital and one big piece, so I was told I would have to replace the entire instrument cluster. All this advice came from people who never actually looked at the car! I am skeptical and open-minded about this, and I would appreciate any help figuring out what to do about repairing it, or find out for sure if I have to replace it. I don't want to order a replacement or buy a used one without knowing if I can repair my guages as the cost of even a used replacement is over $500 in my area.

One additional issue related to the instrument cluster is that my hard top and my soft top will not operate any time that I drive the car. My local Mercedes repair shop spent HOURS diagnosing this and finally said that it is probably because the computer is detecting some fault with the speedometer, and as a rule of safety, it disables the driver's ability to operate the (soft and hard) top because it assumes that the car may be moving. So I was told that i must repair the speedometer and see if it fixes the top operation as well. It is currently really annoying after driving the car each time, having to open the hood and connect a reader to the computer, read out the error codes, erase them, and then be able to operate the top!

Any help on repairing/replacing the cluster, and where to find a good used cluster (preferrably the lighter backgournd AMG look) would be much appreciated.
 
#3 ·
The speed signal for the speedometer on a 1990 comes from the transmission. From January '94 it comes from ABS or another controller. If your cluster's odometer is electronic instead of mechanical, it may be that your cluster is fine and you simply have a compatability issue. In that case you could sell it on eBay for a good price.

The cluster processes the speed signal and outputs an analog to the climate controller, the Combination relay module, and the soft top controller. The soft top operation will definitely not work if you have a code set for this signal missing. The specific code number is "29". I can't believe a dealer spent hours without realizing this.
 
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