1968 Dart gauge help

So I bought my 17 year old daughter a dart rat rod to drive to school but the gas and temp gauges do not work. I pulled the cluster to clean and ground the voltage limiter and while I had it out decided to replace the headlight switch because the dash lights are not working either.I got the switch changed out and the cluster grounded and cleaned up but after installing it I went to hook up the battery...pos terminal on.. neg terminal on and BAM the fusible link smokes! Now I am pretty good with cars EXCEPT with electrical! I do know that the amp gauges are not good in these cars so can I test the gauge now that I removed the cluster again? PS- the wiring on this car looks to be all original and for the most part never butchered and the bulkhead looks good as well.Here are a few pics of the cluster after cleaning up and being grounded (got these tips from other post on here prior). Thanks in advance to all that can help... John

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