need a/c help, chiltons doesnt have the info i need....

having a problem with my ac in my 2000 cherokee, its blowing fuses for the ac clutch. checked the relay it works, i checked continuity on both wires going to the ac clutch, reads a direct short. this is with power off, should they read open or closed? i belive my clutch is shorted blowing fuses, but need to verify before i go buying a new one and waste my time and money. thanks

Do you have a single wire that splits into two? One going to the clutch and the other to a ground on the compressor housing?

When I checked resistance from the connector to the ground I got just under 4 ohms. If you have the one split into two, there's a diode in the wire that connects to the ground lug. Take the ground lug off and try it again.

I assume if you disconnect the clutch and turn on the A/C switch, the fuse doesn't blow. Has it thrown a code?

no code thrown. i couldnt disconnect the wires going to the clutch. at least they look like a direct connect into the clutch. the clutch is still on the car. the wire harness going to it doesnt have any disconnects, well at least what i can see. i havent traced the harness all the way back. it has three wires going to the clutch, all seperate. two into the housing and one grounded to the housing. i will go back and see if i cant find a disconnect along with wether or not those wires split out.

Check down along the harness starting at the clutch. The bundle should have a disconnect. Mine's an '88 so it may be in a different location from yours.

okay so i found out why its blowing fuses, also why it appeared it didnt have a disconnect. the harness was pinched between the head and the coil pack rail, thus shorting it to ground. i have another question before i repair this wire, it does have the diode and i was checking it to make sure it didnt blow. well it reads shorted both ways but the ground wire is still connected, cant reach the screw with a screw driver. will the ground being connected cause it to read shorted both ways? i checked at all three wires they all give the same reading. also what is the purpose of this diode and is it just a regular type?

If you can't disconnect the ground, then it's likely reading through the coil in the clutch. This should have a pretty low resistance.

The diode typically helps with voltage spikes when the clutch engages and disengages and helps dissipate any residual voltage to ensure the clutch completely disengages.

I'd say fix the break and try it out.

okay that makes sense, just wanted to make sure no damage would be done to the clutch if the diode was shorted, it probly isnt, but while its apart do it right. thanks for the help

Diodes don't short out--they blow, like a fuse. I'd think if you put the positive lead of your ohm meter to ground, and the negative lead to the "pluss" side (side that goes to the battery) of the clutch coil, you should read less ohms than the other way arround, which would be measuring the clutch coil resistance. This would be looking at the diode in a "forward biased" position, showing the least resistance of the diode. However, forward bias resistance differs between different diodes, so I can't give specific readings, only "relative" readings between the meter leads in one position versus the other position. You'd expect a difference of 3 to 4 ohms (with the diode in the circuit), so use your lowest scale, otherwise it will appear to be shorted both ways.

got it fixed, was just that wire. thanks again!