Olds Custom Cruiser Instrument Cluster Issue

*** This is a cross post to the data I put on the impalass forum. Just thought I'd share here in case some users don't overlap ***

This post is to share the issues I've had swapping an Olds Custom Cruiser instrument cluster into my Caprice. I'll share the issue I had initially, how it's morphed over time ,and the only solution I've found at this time.

Successes and failures have been shared to hopefully aid everyone in case they have a similar issue.

The Problem:
When I installed my Custom Cruiser cluster, I had an issue where the the Tachometer pegged out at max reading and did not move during use. Even if I reset the needle to zero before trying to start the car, my tach needle would jump to between 3k and 4k on the tach before starting and maxing out.

I know this issue was related to the cluster and no my custom wiring due to using a Roadmaster cluster as a test subject as well. This cluster had no issues with the tach.

Gauge Measuring instrument Odometer Font Temperature



Some Research:
While trying to find information on the topic, I found a few things that seem to be related

This problem seems to come up on other Olds Custom Cruiser Clusters, not just mine.

There is a similar problem on 3rd Gen Camaro Tachometers of a similar vintage (1990 - 1992). The issue in this scenario seemed to be related to the resistance in the circuit. The link to the thread is below if anyone is interested.

90-92 Tachometer fix.... - Third Generation F-Body Message Boards
Electronics - 90-92 Tachometer fix.... - As many of you guys know... barely anyone has a 90-92 gauge cluster with a tachometer that reads properly. They almost always read too high. There has been a multitude of posts regarding finding a solution or a fix for this, but to my knowledge, no...
www.thirdgen.org


What I Tried to Fix the Problem:
I did my best to attack the problem systematically in an effort to narrow down the issue as effectively as possible. As mentioned previously, I used a known good Roadmaster cluster to isolate some components for review.

Step 1 - Swap the Olds Custom Cruiser Face Onto the Roadmaster Cluster Board
This test changed what I saw from the defunct tachometer, but I still didn't have any response when revving the engine. The tach also was still stuck in the middle of the range (around 4k)

Step 2 - Swap the Olds Custom Cruiser Stepper Motor and Roadmaster Stepper Motor
This step involved removing the tachometer stepper motor from the Roadmaster cluster onto the Old Custom Cruiser face. The circuit board from the Custom Cruiser was used in this trial. This trial also proved to be unsuccessful at fixing the problem (tachometer was still stuck).

Step 3 - Swap the Olds Custom Cruiser Tach Stepper Motor with a Speedo Stepper Motor from Civilian Cluster
This idea came from my research of early 90's GM clusters. I found that some of the trucks used the same stepper motor for the tach and the speedometer. Since I had a donor cluster for the connector to my harness, I took the stepper motor from the speedo and tried it on the tach. However, the needle diameter seems to be different between the two, and thus not a good substitute.

Step 4 - Check the Custom Cruiser Circuit Board
Admittedly, I probably should've done this step sooner, but I was partially convinced that my issue was in the air cooled stepper motor after the results of Step 2. While looking at the circuit board, I found at least three sets of soldering joints that looked like they were cracked. Enough so that the resistors would actually wiggle in the board when I touched them (pictures below). Solder was removed for each joint using copper braid and reapplied. I checked cluster function after each change using a roadmaster stepper motor on the Olds Cluster. None of the changes fixed the problem, but they seemed to get incrementally better with each fix. First fix made the tach stop maxing out and peg out instead at about 4K, second fix allowed for some movement of the tach (but it wasn't as smooth as desired). Third fix allowed the needle to jump to the traditional 4K at startup, but the needle would then make a clockwise 360 degree sweep before coming to rest in about the same position again.

Circuit component Electronic instrument Electronic component Audio equipment Electronic device

Audio equipment Shelving Font Electronic instrument Circuit component

Step 5 (the fix) - Swap Parts with a Roadmaster Cluster
In a grasping step, I finally chose to make a far-reaching change to see if I could make something work. The changes made this time were as follows: I swapped the tachometer stepper motor from the Roadmaster cluster to the Olds Custom Cruiser face, I then used the Roadmaster circuit board to run the cluster.

Upon initial startup, I was concerned I somehow still had problems. The needle was sticky on the tach and did not sweep smoothly. Upon inspection, I found that I had reinstalled the tach needle too tight and had induced this failure on accident (don't do this). When I loosely installed the needle to check performance again, everything worked perfectly!


Conclusion / Wrap Up
In conclusion, it seems that the issue I experienced was a twofold problem, as I could not get rid of the issue by swapping just the stepper motor or the circuit board. Only using both in conjunction allowed me to restore proper function.

Perhaps this is due to an issue with a specific run of circuit boards? I noticed that the Olds Custom Cruiser board had a serial number ending in "B", but the Buick Roadmaster cluster board number ended in a "C".

Circuit component Font Urban design Line Hardware programmer


Unfortunately, I ended the night on a low note. While removing the Olds Custom Cruiser cluster face for the last time, I put my tool in the exact wrong spot and managed so separate the face from the backing. This sent two white cracks down the center of the cluster face where the separation occurred. I'm heartbroken at my careless error, as I enjoyed the look of this cluster more than my Roadmaster, but thus is life.

Please learn from my mistake and avoid the same disappointing fate.

I experienced the needle issue years ago when I was trying to fix a cluster. The problem I had was in the circuit board, and switching it fixed the tach. I used a Buick board in my OCC cluster, and it worked properly without any further effort.

You're absolutely right. I came to the same conclusion, but took the long way to get there!