Needle Gauge Cluster Quirks

[firebane]

I just picked up a 93 rclb truck with needle gauges. I'm not sure how accurate some of them are but I know for a fact a few of the gauges are being silly.

The first gauge is the tachometer gauge. It has a tendency to be a bit bouncy in the high rpms... I'm thinking distributor related? The truck has 328,xxxkm on it and I have no idea the last time maintenance was done.

The gauge is the volt meter. When the truck is running it shows +/- 19v but pulling a reading from the battery directly its showing a steady 14.25v. So I know from the battery to the rest of the truck voltage is good but the cluster is showing the wrong reading.

I haven't really dug deep into it yet but thought perhaps someone may have had a similar problem and know a fix.

 

[Dylan1991_1500]

Not unheard of. I have a temp gauge that reads higher than what the cooling system is actually at.

 

[Curt]

Not unheard of. I have a temp gauge that reads higher than what the cooling system is actually at.

Not sure if this applies to pre-Vortec engines, but the engine in my '96 has two sensors for the temp gauge. One sends the signal to the instrument cluster, and one sends the reading to the PCM. Maybe the coolant temp sensor reading to the instrument cluster is faulty.

 

[Dylan1991_1500]

Just replaced the gauge sensor (the sensor next to cylinder #1 spark plug) and no change. Changed the Tstat and flushed the coolant. New water pump. She still reads the same. Not overheating so I assume the gauge is off after 25 years.

 

[firebane]

So I just want to update this. Driving at night with the lights on and you put the signal lights on the voltage meter drops and then bounces in sync with the blinking light.

Thoughts?