1991 500SL Instrument Cluster

[mooneypilot]

Needles jump and warning lights flash on instrument cluster when turn signal activated.

MB dealer diagnoses "bad instrument cluster". Old style motherboard discontinued, entire cluster, including analog guages and LED odometer replacement must be purchased. Prices for new range from $1000-1500.

Any rebuilders out there?

[speace]

I am in the same boat on my 92 500SL. My shop said the same thing. convert the cluster to the new model $1000.00 +

I had them replace the turn signal switch anyway since it sometimes would not cancel. The TS switch has not caused the problem since, but it has done it ONCE in the last month when I turned on the headlights... The demon just moved into another gadget! Darned it, thought I had it licked...

My take on the problem is that the voltage regulator chip for the cluster is getting a spike from the sudden usage of current elsewhere in the car. The regulator seems to shut down and then reset itself. Surely there is an improved regulator or a place to add a surge suppressor that will fix this without replacing the entire cluster with the expensive digital kind...

Let's hear a reasonable solution to this!

[mooneypilot]

I sent mine out to a rebuilder; they couldn't find the problem, and therefore couldn't fix it.

[6.9me]

i just had mine rebuilt( on an exchange unit) for my 92 300 se which should be the same
mmbz auto repair in glendora california

[speace]

That's interesting... Was your cluster doing the same as ours? Just intermittently resetting itself when you hit the turn signal or do something that causes a power glitch?

If so, did you take your car to their shop, or remove your cluster and send it to them? May I ask what they charged?

If someone out there knows how to fix these for a reasonable fee, they can get a lot of business from people like us out there watching the lights blinkin all over the dash... LOL

[6.9me]

its about 1/2 the dealer cost and he's telling me that some are now repairable ..he took it out of the car and replaced it(they need the vin# so that the milage will be the same) ..its a common problem he said cause the circuit boards are so thin they crack

[mooneypilot]

Since my problem is intermittent, I've always thought it was a ground or circuit board problem.

Where is the shop that repairs these boards?

Or, did you say you know a source of repaired boards?

[6.9me]

i live in so cal and this is a mechanic that has been in the family for many years ..he can give u all the details:
his name is mirek
mmbz auto repair in glendora ca
(626)335-2013

[blackjackrob]

If you have an early 90-93 sl and your instrument cluster has gone haywire I am willing to bet you may have jump started it prior to it going bad. I have a 91 500 sl and the same thing happened to me just after I did. I found out the dealer wanted $1500 so I call BBA Remanufacturing in NJ. They said these things were extremely sensitive to over amperage. I sent it to them and for about $250 they rebuilt it and sent it back with a warranty.

Hope this helps.

[DieselPaul]

I've used BBA remanufacturing as well, they did a throttle body for me as well. Very happy with them and their work.

[mooneypilot]

I think mine was damaged by jump starting. I finally found a solution at Beckman Technologies in NC in 2004, for about $350. They quoted a higher price if I bought it direct, rather than through my mechanic.

I sold the car in 2011 and now have a 2006 SL55 AMG.