[sac1248]

We gave our 89 Chevy S10 Blazer to our grandson. The gauges stopped working when stereo system was installed by electronics store years ago. Can those electronic gauges be replaced with dual gauges or does the wiring have to be checked. It's a one owner vehicle with about 170k miles on it. 4.3l vortec. The digital speedometer works and the rpm, I think., But not the fuel or others, so we have no way of knowing how much fuel it has. Any help/info is greatly appreciated.

 

[oldeerslayer]

It should have ben taken back immediately to the electronics store to be repaired. Too late now I'm sure.
If you can locate an 89 analog gauge instrument cluster, hopefully with the dash wiring harness, it can be converted to dial gauges. Be sure the dial cluster works before purchasing it and that it has the same transmission. The wiring modifications should be done by a professional. If you can find someone willing to take on repairing someone else's mistakes. Figuring out what the last shop screwed up will be the tricky part. If you're lucky they may be able to get the digital cluster working, but at this point you don't know if it's OK or not. They weren't known to be extremely reliable. The one thing in your favor is the fact that only the display is digital. The wiring to it is all analog.

 

[MyWorkInProgress]

You can send the digital cluster out to be repaired, it’ll be a couple hundred bucks but you don’t have to worry about changing out wiring connectors.

 

[oldeerslayer]

I believe his problem is he doesn't know what his problem is. Could need to be rebuilt. Or not. Depends if the stereo shop screwed it up when installing the stereo system or maybe they only screwed up his wiring or maybe it was just coincidence that it stopped working while they had it.
He needs to get an 89 factory service manual that has step by step diagnosis charts for each gauge listing the correct procedure to find out what is wrong with each gauge. He also needs to get the installation manual for the particular stereo he has and verify all the wiring was done correctly. Hopefully it was a high end unit with a good install manual. Cheaper ones tend to have pretty poor instructions. Just google the brand and model and "installation instructions"
Here's the least expensive 89 Blazer FSM on eBay:

OEM 1989 CHEVROLET S-10 BLAZER Shop Service Repair Manual | eBay

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Here's the 89 S10 Blazer cluster wiring showing both pinouts:
Open the diagram in a new window or tab and click on it to see it larger and clearer.

I start by turning on the key without starting the engine and unplug the oil pressure sender and dark green temperature sensor one at a time. Then ground each of those wires one at a time while watching the gauges. They both should go from one extreme to the other when open or grounded. This will tell you if the gauges are any good. Could just be bad
senders? Same for fuel, but that's a lot more work to unplug the sender.