Problem with old EI US-8A engine analyzer

I have an EI US-8A engine analyzer on my O-360.

All the temps appear rock steady in the windows except both the EGT and CHT for #1. These bounce around all over the place.

Before I start taking things apart, any recommendations on where to look or troubleshooting tips?

My first step was to swap the leads with the another cylinder and see of the problem stays on #1 display windows or follows the probes.

I'd suggest snipping off and replacing (recrimping) the blade connectors. I could send you some if you don't have any Rosie