1. I have NEVER seen an Icemaker trip a GFCI (39 years)
2. I HAVE seen a Refer (RV) trip a GFCI due to a faulty 120 element
3. If you suspect the refer is ON the GFCI circuit, just turn the refer OFF. If the GFCI fault goes away, then replace the refer 120 element/s. Doug
PS, if you have NO idea what and how various wires are used/connected. STOP. You can create more problems and when you decide to have a professional look at it, it will be harder for him to get various receptacles wired up. It will increase your bill.