Electrical gremlins- Power locks, cruise and front speakers...

Just picked up a pretty sweet, lower mileage '99 XJ for a project.
Hoping someone might have some instincts on this and if any of it might be related.

-Power door locks don't work. They make a noise- kind of a squeal, like an actuator or solenoid working, but no lock/unlock. There is power going through there. They will lock and unlock with the key.
Power windows do work from all 4 door switches.

-It has the nicer factory stereo with CD, EQ, etc. Front speakers don't work, but the rear one's do. One strange thing- when I start driving, the stereo has no display-just a black screen. In a little while, there is a dim display, like you'd expect to see at night. In a little while longer, the display is bright, like it should be. Strange...

-Cruise control is intermittent. Sometimes, the on/off switch will turn the cruise light on, sometimes it won't. Sometimes, the cruise will kick in and run for a bit, sometimes it won't. Sometimes, cruise will hold speed and then drop off/disengage. Usually when going up hill. Horn and turn signals all work.

Jeep runs, drives and idles great.

I know the passenger side door module controls multiple functions and also whether the other locks will work from the drivers switch. Wondering if anyone knows of a possible common denominator here, or if I have multiple issues...?

Thanks for any help on this!

Dirk

What does the wiring between the doors look Like?
Pull the No it back and inspect the wires, many times they break or begin to after years of opening/ closing doors.

Haven't looked at anything yet electrical yet.

Just hoping something might jump out as a possible focus.

If stereo is acting funny that could be part of the problem with your speakers. If $$ is tight I’d borrow a working unit or get one from the junk yard and see if that fixes the speaker problem. If you have a little extra cash you can get a head unit with Bluetooth (no CD) for about $100. Could also be wiring between the doors as mentioned. A broken wire passing between the drivers door and inside caused drivers side rear window not to work.

Drivers door and tailgate wire harness issues are very common. Start with a physical inspection at the rubber boot and continuity testing of the driver door wire harness. 12 volts positive shorted to ground or shorted to the speaker wires will cause the front speakers to not work and/or cause the head unit to go into protect mode and shut down. You can test the front speakers function on the rear speaker wires very easily.

Use throttle body cleaner to clean the door locking and latching mechanisms, and lubricate them with a CLP type gun oil. The weak lock function may be caused by broken/damaged wires in the drivers door harness, or poor ground.

Problems with the cruise control steering wheel switches are also common and should be a primary suspect, especially with the intermittent nature of the malfunctions. Check the entire system and the vacuum ball for damaged hoses, fittings, and leaks