I have a early 99 F-250 4X4 w/ the 7.3. I took my truck to have a computer check on it the other day. The guy hooked up the scanner to the data link connector and said that the plug was not giving him power to turn on the unit and run the test. I checked the fuse panel and was missing the #3 fuse which covers the data link connector and the cigar lighter, I installed the fuse which seems loose and still nothing. I got out my test light and tested the plug for power and ground. I have 7 wires running into the plug. Two of the wire has ground, but none have power. There is a wire that is blue/ a green stripe that looks like it could have went in the plug but there is no each pin in the connector for it. I also looked at the wiring diagram and said that it is part of the "power take off" ? The ground for the plug and cigar lighter is the same, I traced the ground and it goes to the main wire harness that runs through the firewall. Does any one have a idea what the problem could be? It has me stumped because everything else works great. The cigar lighter also does not have any power.

Sorry for the long post, but I am trying to give you guys as much stuff to work with.

 

Do you have power at the fuse holder? If not, there's your problem.

 

I'm glad this problem was brought up. I had the same issue this weekend trying to pull codes out of mine. I can't offer any suggestions at this point, but will dig into it tonight.

 

I forgot to check the fuse holder. da

But I thought it would be weird to lose power just to one fuse.

 

If you are still having a problem these are the measurements I got this morning.

 

The PDF I posted in prior post is to complicated. Here's a simpler picture.

 

I did those measurements. #2 didn't give me anything, and #16 didn't give me anything. All the rest was the same.