Hello. Please excuse my english spelling. Swedish -99 blazer owner.

So. Bought the blazer cheap with some issues.
The gas guage and the enginge tempguage is stone dead.
The other warninglights works when I turn on the ignition, when I start the car, dead - all of them.

Sometimes all the lights goes completley disco on me. Revcounter dancing like nothing els.
Oilpressure, oiltemp, speedo works fine all the time.

Help me.

 

So you are saying the lights are also turning on and flashing? Not sure if a '99 Blazer is included but many Chevy's from late '90 well into 2000's had issues with the gauges caused by bad stepper motors, but this didn't make any warning lights flash.

Since it is the entire instrument cluster I would pull it out to make sure you have a good connection at the connector. If there is nothing else going on related to what you see on the instrument cluster, you could pick up a used/refurbished one off eBay or check the junkyards.

Oh, if you are handy with a soldering iron...try replacing the electrolytic capacitors on the cluster, they dry out with age and will cause all kinds of voltage problems.

 

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