I have an 83 Tbird with a caburated 3.8. The check engine light came on but I can't locate the Mcu port. I have checked everywhere but none and even no capped wires.

I did check a ford diagnostic manual that had a chart for models. It said that they only put the port on the '83 3.8 California tbird cars.

But wouldn't there be a diagnostic port if there is a check engine light? None of the ford forums have been able to help. I've been to many junkyards getting parts and the port is always in the same place. But I haven't found an 83 with a 3.8. Thanks

1 Answer 1


According to this article


The first ODB systems only lit a dashboard light in the case of a problem with no further information about what the problem was. Those early systems didn't have a port to connect to. That would be why there is a check engine light, but no port. It also refers to the first ODB I systems coming out in 1989 for Ford vehicles.
Based on your Ford diagnostic manual it sounds like only the California versions of the '83 T-Bird had the port. Since it's showing a location, and yours isn't there it sounds like your car is not a California car and it's too early to have the port.

  • If it has it, it will be in the engine bay, next or close to the fuse box.
    – race fever
    Jan 15, 2016 at 21:34
  • Thanks for the help. I have looked everywhere for it. I was just wondering how it would get inspected with a check engine light on. Would they just replace every sensor? I will probably just get antique tags anyways so no inspection needed in my state.
    – Kyle
    Jan 15, 2016 at 22:26

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