A/C blows fuse after wreck repair

SC RIGGR · **Posted:** Tue Jan 14, 2014 10:45 am

We have an '05 that was involved in a fender-bender last September. It didnt look too bad, but the hood and everything forward of the engine was replaced. I even supplied a Hayden fan clutch for the rebuild. Unfortunately we waited a month to get a fan it needed. Luckily we had a loaner car from my Father-in-law. After the fan arrives we get the Liberty back and notice after a couple of days the A/C doesn't work. Looking under the hood, alot of oil residue was on the top radiator support. It seemed the schrader valve on the A/C line was leaking. Back to the shop again, they said the entire line needed to be replaced. Another wait of a couple of weeks for the new line to arrive. Finally it is installed and we have supercold AC, finally. Since we are experiencing cooler weather it takes about a week to realize it stopped working again. After yet another trip to the body shop they show me a yellow fuse and tell me the clutch is wearing out and drawing more current, so they have "FIXED" it with a 30 A fuse. Again after a few days it has stopped again. Has anyone had problems with their A/C clutch fuse or what has the shop overlooked?

papaindigo · **Posted:** Tue Jan 14, 2014 12:04 pm

I'm not much on auto electrics or AC systems but what you describe makes me worry about the shop. If the schrader valve is leaking the solution is to replace the schrader valve not the whole line and if a fuse (presumably the F21 one in the power distribution center in front of the battery) blows because of a higher than normal power draw you NEVER EVER just throw in a bigger fuse as the solution is to find the problem and fix it rather than risk melting the wiring harness and burning the vehicle to the ground. Off hand I'd suspect some collision related damage to the AC compressor although if the AC system bleed out and they did not add oil during the system recharge it is possible that the compressor is intermittently seizing up.

Just thoughts to get you started.

SC RIGGR · **Posted:** Tue Jan 14, 2014 1:16 pm

I also thought the valve was replaceable, but the shop said otherwise. Forgetting the oil charge had not occurred to me. I will have to ask them. It would not surprise me since they also used universal coolant AFTER I asked them to use the G-05. I hope there is enough anti-cavitation in the remaining fluid in the block. I was also amazed at their FIX!

tjkj2002 · **Posted:** Tue Jan 14, 2014 8:56 pm

SC RIGGR wrote:

I also thought the valve was replaceable, but the shop said otherwise. Forgetting the oil charge had not occurred to me. I will have to ask them. It would not surprise me since they also used universal coolant AFTER I asked them to use the G-05. I hope there is enough anti-cavitation in the remaining fluid in the block. I was also amazed at their FIX!

In some cases you must replace the whole line if the threads for the schrader valve are messed up.I've seen that a lot when owners think they can fix there own AC systems and over charge it and latterly blow the valves out of the line.

Billwill · **Posted:** Wed Jan 15, 2014 4:04 am

You can download the KJ Service Manuals from the link in Sams Noob Guide...includes circuit diagrams.
First pull out the relay for the air-con to see if the fuse still blows....this rules out the AC clutch as the culprit.
Then put relay back in place but disconnect the clutch connector at the clutch...this will point out a wiring problem if the fuse still blows.

I had a front fender bender in my 2002 CRD.

After getting the Jeep back from the repair shop I had about 6 seperate wiring issues which I had to fault-find myself...including an AC issue!

The wiring harnes for the KJ engine bay does not take the shortest route at all....more like the Beltway going around Washington DC!

So even the trip from the fuse-box/ AC Relay to the air-con clutch is not just an 18 inch journey but the harness travels around the front of the engine bay under the radiator...where the damage normally occurs...around the air-filter, under the windscreen and eventually to the AC Clutch...about 7 feet of wiring. This is how it works on my RHD Export model....your LHD model may be different.

In my case I believe the harness was damaged somewhere up front although no damage could be seen...I had to measure out failing wires to look for leakage to chassis or other wires. These wires I then cut off at both ends and replaced with short sections of wire going direct point-to-point over the shortest route and marked my changes on the circuit diagrams for the next owner of my Jeep to find. :wink:

So you may need to do the same thing if it appears to be a wiring issue and not the clutch itself...cut off the relevant wire at both ends and replace it with a short piece of new wire and tape it neatly in place.

SC RIGGR · **Posted:** Sat Feb 22, 2014 12:34 pm

So it has finally warmed up here enough to prompt me to further investigate the A/C fuse issue. Looking in the underhood panel, I found a 30 A fuse in the place of 20 A that should have been in slot 21. This was the "fix" by the body shop! After replacing that with the proper 20 A fuse, I pulled the A/C relay and the Cabin Heat relay. Looking at the wiring diagrams showed me these are fed from the same fuse. I reinstalled the A/C relay and started engine. Pressing the A/c button energized the A/C clutch and I monitored the clutch in the engine bay while I had my finger on the relay. I could see the clutch cycle and feel the relay click. All worked fine for several minutes. However when I tried to reinstall the Cabin heat relay the fuse blew again. As the wife had to leave with the Jeep, I could not investigate further.
My cabin heat clutch on the viscous heater has been disabled for a while now, especially since the friction splined disc is sitting in the mesh bag in the cargo area. Awhile back I tried replacing the viscous heater bearing when diagnosing a Really Bad underhood squeak, which turned out to be the Alternator pulley clutch causing the tensioner to complain LOUDLY. In that process I lost the shim washer that keeps the proper distance for the Heater clutch. Also the heater clutch retaining bolt has disappeared, I found the splined disc almost falling out one day.
So my question is, could something affect the coil in the clutch since the splined disc is removed?
Also does anyone know the dimensions of the clutch shim and bolt? I havent seen any part number except for the whole heater unit. Thanx N

A/C blows fuse after wreck repair

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