99 jeep shaking like crazy

my 99 jeep cherokee vibrates like crazy when the a/c compressor is on. shakes so bad that i thought it was a problem with the balance. any ideas or do i just have a bad compressor?

Consider that the AC adds quite a bit of load to the engine. If yours is performing marginally then the AC compressor will give it a load it can’t handle. So my guess is that you probably need something simple - like basic maintenance stuff. Like maybe new plugs & wires, air & fuel filters. But you didn’t even say how many miles are on it let alone anything about the state of maintenance items so its anyone’s guess.

160k, relatively good shape, serviced regularly and recently, and only driven about 2000 miles a year. the engine doesn’t seem to be bogging down or sound any differently when i looked under the hood. thanks.

Just because its running rough doesn’t mean it will “seem” to bog down or sound different.

Check out the plugs & wires. Do any other maintenance even close to due. (When some people say “serviced regularly” they mean oil changes). Check the fuel pressure.