When many people think of SUVs, they think Jeep Grand Cherokee. This well-known mid-size SUV has been around for awhile, but don't think that means they've perfected the electrical system. They haven't. The longer you keep your vehicle, the more electrical problems you're likely to see.
Beware of leaks because they can cause electrical problems from air conditioning to cruise control malfunctioning. Vacuum lines, in particular, are susceptible to small vacuum leaks. Patch or replace the lines.
Consider a possible problem with the PCM or ECM computer if multiple electrical problems exist, from repeatedly blown fuses to gauges that go haywire. When it's that bad, you might need to replace the PCM. Some Cherokee owners have saved money by purchasing a rebuilt one. Take a look at the oxygen sensors. If they appear pretty damaged, you should replace them too.
See if replacing your ignition switch will help if some electrical components work when the key is in the start position, but all your engine does is make clicking noises when you try to start it. Another possibility in the Jeep Cherokee is a blown fuse in the fuse box under the hood. This one is close to the battery.
Examine your battery thoroughly before deciding to replace it, particularly if some of your electrical components still work. Clean the battery posts and inside the battery cables. Make certain that connections are firm. Jeep Grand Cherokee gauges and fuel pump don't work when the battery is low or dead.
Prepare for a lot of work if your symptoms point to a leaky heater core, a common problem in the Grand Cherokee Laredo. To get to the heater core, you must remove the dashboard, console, computer and coolant tank. Be very careful about reattaching everything or you'll finish the job and find a whole new set of electrical problems.
