1996 Jeep Cherokee Voltage Drops Under Load

I own a 1996 Jeep Cherokee Country with the Class III trailer towing package. I purchased this vehicle new. During the past three years, I have observed a problem with the electrical system voltage.

When I start the engine after several hours of non-use, the gauge indicates 13 - 14 volts. During engine idle rpm, if I apply an electrical load such as the headlamps, the air-conditioning, the rear window defroster, or turn on the fan to high, the voltage drops by 1 or

2 volts. If I turn on multiple items, the voltage drops to the threshold value that causes the red GEN lamp to illuminate. Turning these items off, does not restore the voltage to 13 - 14 volts. I must turn off the engine, then restart it. Prior to three years ago, the electrical system would support a full electrical load at engine idle RPM.

If I drive the vehicle after a cold start, and keep the engine speed above 1,500 RPM and then apply a full load to the electrical system, sometimes the voltage begins to drop, sometimes it does not. Once the engine reaches normal operating temperature, this problem occurs less frequently, but it still occurs from time to time.

This problem seems to occur regardless of outside air temperature, humidity, rain, snow, or other environmental conditions. A local automobile repair shop, with whom I've done business for fifteen years, was unable to determine the problem. Any ideas?

On an unrelated (hopefully) note, when the air conditioning is operating in the summer (and obviously the defrost in the winter), the vehicle produces a loud squealing noise when I turn the steering wheel. The noise would persist after relieving the hydraulic loud on the steering system, and would only cease after turning the air conditioning (or defroster) off for two seconds, then back on. During the last twelve months, the squealing noise always occurs immediately when I turn on the air conditioning (or defroster) regardless of steering load. If I keep the engine RPM low for about thirty seconds, the squealing noise ceases, even though the air conditioning compressor is still turning.

The Jeep dealership that sold this vehicle to me could not determine the source of this problem after three visits. A local reputable repair shop was also unable to determine the problem. Again, any ideas.

Thank you.

Reply to
Kurt R. Todoroff
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Kurt R. Todoroff did pass the time by typing:

Several things ranging from battery/wires/alternator/slipping belt/computer

Clean the battery terminals and double check the wires. Check the battery water level to make sure you don't have a low cell.

You didn't say what engine but for the I6 check the ground wire that goes from the coil to the frame. Also remove, clean and reinstall the chassis ground from the battery. (any place there is a connection)

Examine your belt for any shiny spots and make sure it's tensioned properly. Your year probably has an auto tensioned. If the belt is original, forget checking and just replace it.

Take the battery and have it load tested at a local AutoZone/Pepboys/CanadianTire, etc.

Testing the rest is a bit more involved so start with the above.

Reply to
DougW

Your issues are related and pretty common for anyone who runs mud.

Time or in our case mud will dry out and polish up the face of the fan belt. The belt will still look ok and be properly tight, but it fails under load.

In my CJ7's mud pit days, I would kill a fan belt every season. Mud equals liquid sandpaper. Dust isn't as bad, but....

To test this, I take a cold off engine and see if I can hand slip the alternator pulley. If I can make it slip by hand, for sure it will not grab solid under load. The alternator takes a few horsepower to fire up under load.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Sure sounds like a slipping belt. But to confirm, with the jeep cold (which the dealer likely never did) open the hood, start the jeep ... run around to the front and observe the belt moving ... but the AC compressor not turning ... until the belt warms up (friction) and starts to grab :-)

Reply to
bowgus

Seems to me the power steering is the extra load the belt just can't pull without slipping (that's that squeeling) ... and that the belt is either old and slipping or is not quite correctly tensioned and slipping. I've had vehicles that told me by squeeling that it was time for a new belt and you've probably heard a few drive by usually on a cold winter morning. There is (or was) a spray on belt dressing that I've used in the past more or less as a temporay fix that you might consider trying. If it resolves the problem, then I suggest go get a new belt, or adjust the belt if it's new.

Reply to
bowgus

Seems to me the power steering is the extra load the belt just can't pull without slipping (that's that squeeling) ... and that the belt is either old and slipping or is not quite correctly tensioned and slipping. I've had vehicles that told me by squeeling that it was time for a new belt and you've probably heard a few drive by usually on a cold winter morning. There is (or was) a spray on belt dressing that I've used in the past more or less as a temporay fix that you might consider trying. If it resolves the problem, then I suggest go get a new belt, or adjust the belt if it's new.

Reply to
bowgus

Ok .. all those bizarre extra posts gone ... and this Google Groups Beta sure does remove those posts pronto ... very cool.

Reply to
bowgus

LOL!

Google groups just deleted them from 'your' screen, they are still up on the servers...

Netscape will do that too.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Hey ... I was happy in my virtual world :-)

Reply to
bowgus

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