I took my truck to the shop because the wires harness that connects to the computer (ecm) burned up due to squirrels nesting and biting the wires. The shop told me 500.00+ to chNge the wiring harness and computer. I told him that i purchased a computer online for 169.00. And i coud attach it myself o jus need the wiring done. He quotes me @ 400.00 dollars jus to replace the wiring harness. Am i being over charged??