My 94 Isuzu was missing a keyless remote when I purchased it. I see used wireless remotes on ebay for about $40 or less. Some have an FCC id listed of G57KTX318. Sellers state that your Trooper must have the factory keyless remote installed for it to work which makes sense. How can you determine if it was factory installed? Is there an electronic component clearly visible? Maybe an option code somewhere? Anyone know? Thanks.