I have a 2003 Discovery.
Just the other day I went to plug my scanner in and my scanner said 'no connection'. Plugged my scanner into another car and it worked. Tried a friends scanner and still no connection on my car
Then last night I realized my interior lights weren't coming on and my remote key wasn't functioning.
Looked in the manual and it points to the culprit being fuse number 20. Pulled it out and it was good. Tried another fuse and still nothing.
How would you go about troubleshooting this problem?
Thanks

 

The next thing I would do is, make sure you have power on fuse number 20. Also, pin 16 on the data link connector should be 12v.

 

I pulled fuse number 20 and the radio cut off.
checked for power anyway and yes i have power.
0 volts though at data link connector 16.
Thank you for your advice but what now?

 

Loss of communication on the DLC is pretty common on these trucks. If you do a search on this forum, I'm sure you will get a lot of results. Maybe you could try some of the things that worked for other people.
Beyond that, I would test ALL the fuses in both fuse boxes. I usually use a test light, connected to ground. Then, with the key on, test both sides of every fuse. That way you don't have to pull every fuse to check them. Just remember, not all fuses are going to have power all the time. You just want to look for fuses that have power on one side, but not the other. I hope that makes sense.
You can also use a multimeter. I just prefer a test light for this test.
Beyond that, if you don't find anything there, you may need to get ahold of a complete wiring diagram with computer pinout. You might be able to find one on BBB Industries- Premium Alternators, Starters, Power Steering Products for free. If not, I usually use http://mitchelldiy.com which is about $18.00 per vehicle, per month. But their diagrams and information are usually really good.

 

Attached shows you power is coming from header 0289 to diag. socket. Should be a short wire run. Connector may need to be cleaned or reseated.
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I had a similar problem. It ended up being corrosion issues with 0289 and a couple of other headers.

https://landroverforums.com/forum/di...-repair-57435/

 

Thank you both so much for the information and advice. I hope to work on it tomorrow and will definitely let you know how it goes

 

You guys are great especially number9 for providing the picture and diagram. I found that huge bundle of wires on the passenger side about where your left foot would be. Everything was wrapped in real thick plastic I slowly cut it away and found 3 of those harnesses and could see a bit of corrosion. Sprayed it down real good with electronic cleaner and everything is back to normal. Interior lights, obd connection is working, and the remote key. Thanks so much

 

Good to hear it work out for you.
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That's awesome! Thank you for posting what you found and what got it working again. I'm sure this will help others with this problem.