In my Relay all the accessory plugs don't work and neither does the plug in the rear passenger side. They did work at one time.but now none do. I checked all the corresponding fuses and nothing, they're all good. What steps do I have to take to track down the problem and remedy the issue? I currently use an investor so I can charge my phone. No fun. Thanks everyone for input in advance,

 

The fuse blades may have a thin layer of corrosion built up on them keeping them for making proper contact in the fuse socket. The same can occur in the socket itself.

Repeatedly remove and reinsert the fuse about 15 times to sweep all surfaces clean. Referred to as sweeping the contacts.
If you have any electrical component cleaner, you can also rinse off the fuse blades and the socket. Don't douse the socket. The cleaner is non-conductive and will not create shorts.

If that does not help, remove the fuse and insert one test lead from a multimeter set in DC volts mode into one end of the fuse socket. Touch the other test lead to an unpainted ground surface in the vehicle. You should get 12.6 volts DC, or 14.4 ish volts if the vehicle is running. Make sure that the lead connected to ground is actually connected to a ground. You are checking to see whether the fuse socket is actually receiving power.

If no voltage is measured, try the other end of the fuse socket.

 

Ground circuits also fail, I always test for both power and ground. The socket may not work because of a ground circuit high resistance. I use a test light to check both ways. Connect the alligator clip to power to check for ground.

 

Very true, sir.
I have been negligent in my advice for which I apologize.​​​​

 

Thank you very much gentlemen. I greatly appreciate your input and knowledge. I will try the things you mentioned and update on the outcome.

 

I appreciate everyone's advice. I'll get around to checking that one day soon hopefully. I do have one more issue to ask about though. It's the gas cap message I keep getting and the gas cap was never removed when the message popped up. Now it just says on all the time. What could be the cause for this?

 

The gas cap could be loose, the O-ring could be broken or just dirty and needs lubricating or the filler neck could need cleaning and lubricating. All of these things are easy to do and won't cost you anything as long as you have a can of WD-40 to lube that O ring with.

 

Read the codes, that message is usually associated with a very small evap leak. Since the gas cap is the main reason for that code they added an idiot light for it.