Here a few tips for assembling ISO9141 adapter.

• The tantalum capacitor C5 is the polar one and the positive lead looking toward IC1 chip, see picture below
• The IC2 chip is mounted on the solder-side and the white dot on the chip is facing the Serial connector
• The J2 connector is for programming PIC18F2450 and not being used for kits with already preprogrammed chips