I replaced transformer in my central heating system it keeps blowin fuse and won't kick on

What was it doing before you replaced the transformer?

What led you to believe the transformer needed to be replaced?

The electrician said it was bad it has 3 amp fuse but when I try to put 3 amp fuses it blows right away

Provide more info about system - type (gas furnace, heat pump,? ), brand and model # would be a big plus.

It is a heat pump system Goodman U29 REV A
When I try to replace burnt out fuse it fries as soon as I put it in, sorry to hound you guys butshrt on cash and infant in house

Electric gas split system by goodman

SPDDSM: (Similar Problem, Different Day, Same Method) to isolate

Take a look here and pay attention starting at about post #26.

https://www.askmehelpdesk.com/heating-air-conditioning/repeated-furnace-transformer-burns-280435.html