diagnostic port

I am realitivly new to using a tech II GM diagnostic reader I have used it on my truck a few times I had my truck underwater and had to use it to get the truck to start. I have been driving the truck now for 5 months since, starts great but I have noticed my oil pressure gauge isnt working. Then my gas milage started getting worse. I have had the service engine light on for a while and I know it has something to do with everything that is goin on, but here is the thing......I have a 1999 z71 5.3 push button 4x4....when I tried to plug in the Tech II reader NOTHING...plugged in to my wife grand am...Powered right up like normal. Last time I used it in my truck it worked perfect..it doesnt want to power up at all in my truck...frustrating...sorry about the novel! any help would be sweet!

The ODB-II port get power from the same fuse as the lighter. Does the lighter work?

//2000CAYukon

yeah the lighter works for my gps unit..I tried to hook up the reader to the lighter port also but it didnt work...so I thought it was the unitso then I brought it in the house and plugged in it into the wall..it worked so then I tried my wifes car!....could my truck not be producing enough amps? or something the volt meter is reading normal!

Check the underhood fuse block and make sure your aux power fuse isn't blown and also check your cigarete lighter fuse to make sure it isn't blown. If worse comes to worse, just take your tech 2 out to the car with the wall power adapter to power it up.

If I hook it up to wall power and plug it into the truck it wont hurt it at all right?..Most likely there should be a code come up telling me the reason that the Diagnostic port doesnt have power..............my cigarette lighter works for my gps unit and my power adaptor I dont know why it doesnt want to power up the tech II????? wierd

It worked next post is gong to be a doozie! bunch of codes!.....oh yeah its really wierd how it worked though.....I tried lighter adaptor nothing....so I knew my inverter worked in the lighter so I plugged in the inverter and plugged the wall adapter into that...it worked so I have NO idea what is goin on with that stupid thing.

Did you say "my truck was underwater" ? If so you have a lot to cleanup to do and may have damaged your electrical system.

Did you say "my truck was underwater" ? If so you have a lot to cleanup to do and may have damaged your electrical system.

....yeah.... water intrusion/corrosion is not good for your electrical system. The diagnostic port has a terminal with fused power from the cig lighter fuse under the hood. If everything is powered up off of that fuse except the DLC (diagnostic link connector), i would suspect a break in the wire, or a corroded terminal somewhere inbetween the fuse block and the DLC.