I need help for my Intrepid please

Sounds typical of an overheated contact inside the ignition switch or an overheated terminal in the switch connector. Look for a partially melted connector body at the switch, especially if you use the heater fan on the highest setting often.

The ignition switch is what you stick the key into. It has at least three different circuits in it. You'll need to remove the trim cover under the steering wheel, then the connector is on the left side of the column.

The Body Computer isn't involved with the heater controller. If you plan on replacing it, let me know first because there are some important things to know to prevent problems. It has to do with whether or not your car has the factory installed security system.

There's actually five different switches built into the ignition switch. One feeds the instrument cluster to turn it on. One feeds the message center, overhead console, remote keyless entry module, automatic day / night mirror, and Body Computer. The third switch feeds the radio, signal flasher, and the wipers. All three of those switches are fed from a common wire. Burned contacts will affect only one of those switches. If all three systems are affected, suspect the terminal for the common feed wire.

The fourth switch feeds the heater controller, anti-lock brakes, air bag computer, heater blower, and driver's window switch. That one has its own feed wire.

The fifth switch is only used for the brake warning light test during cranking.

The argument could be made that the inoperative things you listed don't exactly correlate with the switches, but if a set of contacts have overheated but not failed completely, they might let enough current to pass to allow some things to work while others don't. The switch is the best place to start though because that is what all of these things have in common.

At least start with the switch and its connector. If that isn't the problem at least you will have ruled out the easy stuff before going on to the expensive stuff.

I have to leave for the rest of the afternoon but I'll be back tonight if you need the wire colors to check. You'll need a test light or an inexpensive digital voltmeter. To be accurate, the testing will have to be done while the problem is acting up.

WAIT! Before you install that BCM, here's a copy / paste version of my reply so I don't have to retype everything and possibly forget an important point. Ignore the first paragraph but I would have to figure out how to make it make sense so I just left it alone:

Ok, first of all, roll the driver's window down, hop out of the car, use the power lock button on the door to lock the doors, close the door, then wait for at least a minute. The anti-theft system will arm if you have it. Now reach inside and open the door with the inside handle. If the horn starts blowing and some lights start flashing, you have the anti-theft system. This is real important to know when it comes to replacing the Body Computer or the Engine Computer. If you have the anti-theft system, you can use any computer from the salvage yard, but from then on, that computer will only work on another car that also has the anti-theft system. DO NOT borrow a friend's computer if his car doesn't have the anti-theft system.

Both computers have anti-theft programming that can not be undone. If your car does not have the anti-theft system, you must find a used computer from a donor car that also did not have anti-theft, and that can be impossible to find out from the salvage yard since there's no easy way to tell unless the car was running when it was brought in. Even then, they might not have bothered to find out.

When you install either the Body Computer or the Engine Computer with anti-theft programming into your car without anti-theft, the new computer will teach it to the other one. A Body Computer will teach it to the Engine Computer or a replacement Engine Computer will teach it to the Body Computer. At that point the car will not start because both computers are waiting for the disarm signal that's never coming. Both computers will have to be replaced at the same time. If you just replace one of them, it will immediately learn the anti-theft programming from the other one as soon as the ignition switch is turned on.

If you buy a remanufactured Body Computer from the dealer, it will come without the anti-theft programming. It will work in any car as soon as it is installed and will self-program itself for anti-theft only if the system is on the car, when it learns it from the Engine Computer.

I just wanted to get all of that out of the way in case you do need to replace the Body Computer, (Body Control Module) ( BCM).

Okay, now that you read all of that, it is all irrelevant if your car has the factory anti-theft system. Just remember that any BCM will work but if it doesn't solve the problem, it can only be used on another car with the anti-theft system. If your car does not have anti-theft and you install a BCM already programmed for it, you'll end up needing a new BCM AND Engine Computer, so if you don't know the history of the BCM you bought, don't risk installing it.

Did you check the fuses in two places? There's one fuse box under the hood but there's another one that's often overlooked on the left end of the dash. With the driver's door open, you pull off the black cover. The forward edge tucks under the lip of the rubber weatherstrip.

Are you asking why the wires have different colors and what they are for? They're different colors so you can tell them apart and find them in various locations without having to unravel the tape and follow each one when you're tracing a problem. The colors and the colors of the stripes are all listed in the diagrams in the service manual so you can figure out how to troubleshoot the systems and where to take voltage measurements and you can figure out what readings to expect.