Hello,

99 V10 4x4 F350. I have no power to the cig lighter (power port works fine) or OBDII. The fuse is fine, but I changed it 3 times just to be safe. No change. I have the entire dash pulled apart as i figured somewhere along the way someone might have hacked something, but everything looks perfect. Just as it left the factory.

Are there any other gotcha's I should be looking at?

Thanks,

Chris

 

Had the same issue with my OBDII and ciggarette lighter when I bought my truck but didnt know. Turned out to be the fuse. Sorry I cant help but if you find something let us know.

Did you do a resistance check from the wires to the fuse block or anything?

 

Not yet, was hoping there was something obvious I was missing. Need to find a detailed wiring diagram, the one in my chiltons manual isn't very good.

Will let you know.

Thanks.

 

There's nothing to the circuit except a line from the fuse to a splice. From the splice, one line goes to the lighter, the other goes to pin 16 of the OBDII port.

Which fuse have you been replacing?

 

The third one down on the left on the fuse panel inside the cab of the truck. The first on the left is a 20A, second is a 5A and the third is a 20A (i believe this is the one for the OBDII / Lighter). I have no power to the fuse or anything on that circuit. No power to the cigarette lighter and my un-powered OBDII doesn't work, but my battery unit does. I did check every fuse (inside cab and under the hood) with a electrical tester and all were good.

Anyone have a detailed wiring diagram?

 

Pull the fuse (F3, 20A) and check to see if you have "ALWAYS HOT" power on one of its terminals in the box. check the contacts for spreading or other damage. If you do not have power there and everything else in the truck works properly, then it's a failure internal to the fuse box.

If one terminal does have power, identify it as your source terminal, the other will be the load. The load terminal, with the fuse removed for testing, should have continuity to both the OBDII port and the lighter via splice S242.