No codes from EEC-IV

Hey there everybody, Happy New Year. Hope you've been well.

I'm back in New Mex and going a round 2 on trying to figure out what's up with my truck. I'm quite sure the computer is in limp home mode and I feel like the most straight-forward way out of it is to get the emissions codes and fix whatever problem there is. However, I've now tried several times to get codes and gotten... no codes.

I'm following the method outlined in a few forum posts as well as my Chilton's manual. Off for at least 10 seconds, used a jumper wire that I got blade ends for to short the indicated pins, and tried both a test light and multimeter. It's all quiet. I've investigated the harness externally from the connectors by the battery back to the fire wall, I pulled out the computer and looked for any obvious signs of corroding capacitors, and I reseated the connector from the computer to the harness. It did seem like it was a little loose before I started but it seems well connected now. Either way, same result. No codes.

Anyone have any tips here? I'm thinking about either trying to plug in the computer out of its casing so I can try to jumper the appropriate wires manually to verify that it is in fact not the harness, or perhaps just replace the computer. The computer is definitely not the original on this 1986, it's a remanufactured unit.

Thanks for any tips !

TS

I don't have any tips.  But have you compared your procedure with the one set out on our page at Documentation/Electrical/Electronic Engine Control (EEC) and then the EEC-IV and Code Checking tabs?

what is the drivetrain you are having problems with and what are the symptoms

I would want to check if the computer is getting power, i.e. is the ignition switch in fact activating the EEC power relay, and is that device actually sending power to the computer.

Pardon a slight momentary sidetrack... Happy New Year, Mr. TuButis!

Thank you, David! Happy Birthday to you & Gary and all you guys out here!

You are only ~6 months off - either late or early.  But I'll take it.  

Chris is closer to being correct with me!