Needle location on gauge

[onesecond]

So I had had what I thought were some overheating issues, then I thought under heating issues but I replaced my thermostat and my gauge needle will rarely move from the 3/8ths spot once it is warmed up. I'm wondering if I may have messed something up when I pulled the gauge cluster out to tighten the back bolt.

I'll link an image of where my needle sits immediately after turning the car on.

[columbo_01]

Something similar happened to my fuel gauge when I pulled the cluster out to replace the odometer gears. When the car is off the needle doesn't rest where it used too. Its now below the R. Swapped the fuel gauges for a different one - still didn't fix it.

[Gregs///M]

Copper oxidation is a serious problem on these clusters, Its not just the clusters, the wiring harness, fuse box, and all connectors have 30+ years of oxidation and although they may work, they will not work like there were brand new.

Also, the SI board has two batteries on it. There is no such battery that can survive 30 years. So when you disconnect and pull the cluster, there is no way those 30 year old batteries will survive being disconnected from power that long so when you reinstall your cluster, the SI board has failed on the bench. It will need to be replaced. Most of the time, restoring the entire cluster is the cheapest and fastest way to restore accurate and reliable gauges.