94 Jeep Wrangler back shelf rusting

The answer is to replace the cable that flips the cover. What's most likely happened is that the cable has rusted in the lever mechanism under the carpet. This happens because of water getting in through the floor. Remove the drivers seat. When the carpet is up, look for rusted out metal plugs (about 30 mm in diameter) in the floor. Replace and fix any rust or leaks. Replacing the cable can be tedious, usually requires removing the trim in the trunk, and often taking out the back seats to get access. A garage would charge 2-3 hours of labour to do this job.

The moisture in the trunk is coming through into the car with air movement, since the trunk is not air tight to the car interior.

Let's do the trunk first.
Remove the spare tire and carpet and all else in the trunk and dry it out. I would used small space heater or a blow dryer or anything else that will heat and dry the air. If you want to fix the water leak, you will need to find out where it coming from.
The most common place is the gasket around the trunk lid.
After that, a rust hole somewhere in the trunk.
You may find a new gasket hard to find, and if you do, not easy to replace as well.
Finding a rust hole might require you to take a strong light and have a helper to look either inside when you have the light outside, or outside when you have the light inside the trunk, (night works best).
On older cars, I have often made a permanent hole in the lowest part of the trunk to drain out water leaks.
Make a hole about 1/2" diameter of more, so it won't plug up. There are sometimes rubber or plastic plugs you can remove to drain the trunk as well.
Make it so stuff you replace into the trunk will not cover that hole. Carpet holds water, so you may choose to put a new piece of something in there, or nothing.
Read the instructions below on usuing "Damp-Rid" plastic buckets in your trunk.

Now lets go inside the car.
I recommend you dry out the inside with a space heater or blow dryer as well, for a day or a few days.
Then,
Lumber yards and hardware stores and such places sell a small bucket of stuff called "Damp Rid"" This is plastic tub full of white crystals that absorb water out of the air. Put one or two of these in your car on the floor of the back seat and maybe the passenger's front seat. Follow instruction on the container, and they will remove moisture from inside your car.
NOTE: You must be careful because they work with the top open, and therefore will spill accumulated water when you start and move the car, they'll tip over. If you put them in the trunk, don't forget them there.

This can be from one of couple sources. One would be a broken or missing rubber seal in the firewall. Water can and will enter the passenger compartment if the seal is not good or missing. The firewall is the metal between the engine compartment and passenger compartment. There are many penetrations in the firewall for throttle linkage, steering column, electrical harness, etc. All of these penetrations have seals to prevent water from entering. Check to make sure all penetrations have seals. Inspect from under hood and from under the car, too.

Another source is damage to the floor pan. If you went over a rock or jagged object without having enough clearance, it may have punctured or even sliced through the floor - under the carpeting and sound deadening material under it. If you live in a cold area, and the roads are treated with salt or chemicals to melt ice, it may have caused rusting holes to appear in the floor pan. Water spraying up from tires would enter through the puncture or slice and the carpet would wick the water in. It would take a long time to dry and give a musty smell after just a short time. You should inspect the floor pan from underneath the car. Look for punctures, slices and rust / rot. Clean and seal any openings found in the floor pan and firewall.

Fixed windows and glass in the car body are also sources for leaks. The is especially true if glass has recently been replaced. Many times, the back window leaks into the trunk or metal under the rear seat - and flows to the carpeted floor. Look in the trunk at the bottom of the rear window. Side windows can leak, too - so don't forget to look behind trim interior panels on the sides of the back seat. Your leak could be coming from the windshield, too - this will be harder to locate through the dashboard - but you may find water dripping from wires, etc. Look for evidence of water / rust. Clean and reseal body / glass joints when found.

Good luck!

I had the exact same problem with my 1995 neon. It was leaking around the tail light. I pulled the tail lights off and put a heavy coat of RTV silicone on the gasket, and 2 years later never happened again

Sound like not enough fuel. Before you start car put a rag over schrader valve( valve with plastic cap on it like a car tire) on fuel rail and push valve if fuel doesn't squirt out its a bad pump or filter

Hello,
Are you sure this is rust and not oil? Head gaskets can leak one way or the other or not both. Hoping you did not just buy a vehicle with a head gasket leak. Check your oil level and the color of it. Chocolate milk looking oil is a sure sigh of a one form of a head gasket leak. If your oil is low add some and pay attention to if it gets low for no apparent reason. If you truly just have a bit of rust in your antifreeze then perform, or have an anti freeze flush performed. But this alone will not make it smoke.
Regards, Tony

Hello, if the doors aren't closing right you can loosen the bolt that the doors latch onto, it is a torx, then move it up or down so that it closes well. Otherwise you can bend the door pins slightly. What can happen is that the body shifts with the removal of the hard top or if someone unbolted the roll cage to put down the front wind screen. Get the doors going good by adjusting the bolt that the door jam latches onto to keep the door closed. Then tighten everything good. It is common that they don't close right. Also, while you're at it, pull up the carpet where the seatbelts are in front and look for rust on the floor. YJ's are know for the seat belt ripping out of a rusted floor and the passengers going through the windshield. But I still love jeeps. Cheers bro.

more than likely a broken belt in tire but you mite have a bad tie rod or tie rod end, if all that checks out ok than I would start looking at o/d in the trans

I have the same problem with an 08 Rubicon, but on the driver's side. The appearent issue is a gap or seperation at the top of the firewall. The water leaks down the inside of the firewall, saturating the padding under the carpet. Typically the top of the floor map remains dry and the Jeep smells musty. IMHO, this will eventually lead to a rust out of the floorboards.

As for solution, my first line of defense was to return it to the dealer who put some sealent over the seperation. Two months later (I am taking it back in tomorrow) its leaking again. Either they didnt get the gap completely covered (its been a dry summer) or the sealent failed.

My second line of defense is to remove all the carpet from the inside of the jeep and Herculine the entire tub.

Hope this helps!

I had the same prblm with my 1989 Jeep, 6 cyl straight, and it was because of the EGR valve, easy to replace and not too costly. EGR valve is screwed on the motor, driver side, and there is a ±1/2" rubber hose attached. Easy to see if device comes apart, cut by rust.