'86-'89 Corvettes use a powered fuse link and connector that supplies power to the fuel pump and MAF relays behind the battery. The '85 Corvettes do not use relays for the MAF, but instead use a module next to the ECM. This module rarely goes bad; but to check the module on '85 Corvettes, look for 12 volts at connection E on the MAF with the engine running. Then, run the engine for at least 5 minutes, turn off the key, and check for 12 volts at connection D (MAF burn-off). The powered fuse link is a common cause of intermittent MAF codes. Check the connection and wire for a possible open circuit.