Erratic Gauges
The needles pegging when grounding sender wires is normal
If the battery ground had much resistance, the engine would not crank, and if the battery to body jumper had much resistance, the lights would be going nuts.
My guess is there's trouble right in the cluster, maybe the ground plane is not actually grounding for some reason, I don't know.
What I would do is this:
"Plan" on removing the cluster, but before you do, obtain test resistors--or use an old gas tank sender to mimic the other senders. Connect the test resisntance to each sender wire one at a time, test with key "in run" and see what happens.
The old mechanical voltage limiter DOES pulse, but the gauges are so slow to react you don't see them do so.
Does this happen only when running, or both runniing and not running, etc?
Test resistances
The needles pegging when grounding sender wires is normal
If the battery ground had much resistance, the engine would not crank, and if the battery to body jumper had much resistance, the lights would be going nuts.
My guess is there's trouble right in the cluster, maybe the ground plane is not actually grounding for some reason, I don't know.
What I would do is this:
"Plan" on removing the cluster, but before you do, obtain test resistors--or use an old gas tank sender to mimic the other senders. Connect the test resisntance to each sender wire one at a time, test with key "in run" and see what happens.
The old mechanical voltage limiter DOES pulse, but the gauges are so slow to react you don't see them do so.
Does this happen only when running, or both runniing and not running, etc?
Test resistances
