1998 Chevy Blazer Gauge Cluster. Strange

I purchased a 98 blazer, 4dr, 2wd. Everything is in great condition.

I have to drive with an ignition test and lock (interlock) device in the vehicle. To test for breath samples.

I had the device installed this morning, it is wired into the ignition, the lights, and the horn and acts as a relay. If you have alcohol on your breath it will not allow you to start the car / the relay closes.

Before installation the car was fine, and so it was for a while after.

I was installing a new car stereo, so I had to start the car several times while I was testing wires for power to the stereo.

I noticed after I was finished and wanted to go for a drive that my gear indicator lights were out, the gas gauge was out, as were the speedometer and the odometer. The voltage and oil pressure gauges still work.

I read in a forum that a bad ignition switch will cause issues with the gauge cluster and was wondering if this would be the case? Perhaps a wiring problem with the interlock would cause this?

The interlock is also not functioning as it should. It asks for a test to start the vehicle but afterwards it shuts down (powers off) as if the car was off. But the car continues on as normal.

I need to take it to the interlock garage obviously, but would bad elevtrical contacts in the ignition switch cause these issues?5