Is there a way to check the codes on a 94 F-150 without a code reader? There is a large and a small connector under the hood. I've used a scanner to do this but now I don't have a scanner. Thanks, Mike

 

Hi Mike..

Yes,, you can.. If you jump the Signal Return and the Self-Test Input connections you can get the self test codes as CEL flashes with the vehicles check engine light. You can also use a analog meter or test light and get the codes as needle sweeps or lamp flashes straight off the dianostic connector on the Self Test Output.. Here's a simple hookup diagram to retrieve the codes..