92-94 SC3 A/C; Step Inside
05-15-11, 07:03 PM
#1
92-94 SC3 A/C; Step Inside
CC = Climate Control
A/C = Air conditioner
Cliff notes version skip to very bottom............
Quick overview: '93 SC300, 144,000 miles, located in Houston Texas area. Last year A/C started blowing fuse HTR - 10 amp in lower inside fuse panel shutting down Climate Control. CIG fuse blew once. I thought the CC was going bad. Suddenly STOPPED blowing the fuse in late Sept. '10, then started blowing it again last week. Cliff notes version skip to very bottom............
Scenario: Put in new fuse, turn key but not enough to spin the car over. CC lights up normal, all functions visible. Make sure the A/C is OFF, then start the car. Let it idle for 10 sec., then push A/C button. Within 2-4 sec. the fuse blows and CC goes blank and no functions visible on CC and no buttons work. Issue is SOMEWHERE, SOMETHING, is grounding out.
Investigation: Began tracing wires from the TEMP button on the center console from the backside of the console. Thought TEMP switch (above radio ON button) was bad, bought one from a member here (Thanks SC300jz!!). NO CHANGE, fuse still blows when A/C turned on. Followed wires to large grey plug on top of A/C compressor. Checked resistance on the side coming FROM the cabin, no problems apparent (nothing shorting to ground). Checked same on the other plug, no indication of a grounding problem. Figured my Clutch was out. Spent a couple hours looking (online) for a clutch for this compressor, no luck. Back out to look at compressor. See another single wire connection while tracing wires out of connection that I had just tested. It is a single wire and appears to be the power wire to engage the clutch. Can't get tester probes from Multi-Meter into the connection. I leave the plug un-connected, put in a new fuse, turn key but DON'T start car, turn A/C OFF, start car, wait 10 sec. then push A/C button..........fuse does NOT blow
. Of course, A/C does not come on, BUT the fuse did not blow. This says that there is a direct short in this piece of wire. After moving around the wire, I see EXPOSED WIRING!!!!!. Upon further investigation, there are TWO wires, one a power wire to activate the compressor clutch, and a ground wire to complete the circuit.
I separate the exposed wires, make sure they are not touching (grounding) anywhere, put in a new fuse, turn key but do not start car, turn off A/C using the CC, start car, idle for 10 sec., push A/C button on CC.....A/C IS WORKING
. The ENTIRE Problem was the wiring powering the compressor clutch had degraded (leaking Power Steering unit directly above) had broken down the rubber and exposed the wiring.
Fix: Removed the power steering pulley (splined and wiggled off slowly) to have better access, and removed the wire loop holding the wires. This wire loop is VERY important. It supports one of the two pieces that make the electrical connection. It MUST be put back in place so that if you need to UNCLAMP the connection at a later date, it will stay in place. Went to Advance Auto and bought liquid electrical tape (yes, they do make this) and taped over, then applied liquid tape. Let dry (30 minutes). While putting everything back together, idler pulley bolt strips. Quick trip BACK to A/A for new idler, install, start car and A/C is ROCKING!!!!!!
Cliff Notes: Continually blowing HTR fuse when turning on A/C. This would blank out Climate Control, no buttons worked, no power. Traced problem to a bad power wire to A/C compressor clutch. Wire right at compressor had degraded and frayed because of age and leaking P/S fluid at some point in this cars life, grounding out and blowing fuse. Fixed wire (very difficult to get to) and A/C is back to normal. Climate Control functions normally also.
Jim
A/C = Air conditioner
Cliff notes version skip to very bottom............
Quick overview: '93 SC300, 144,000 miles, located in Houston Texas area. Last year A/C started blowing fuse HTR - 10 amp in lower inside fuse panel shutting down Climate Control. CIG fuse blew once. I thought the CC was going bad. Suddenly STOPPED blowing the fuse in late Sept. '10, then started blowing it again last week. Cliff notes version skip to very bottom............
Scenario: Put in new fuse, turn key but not enough to spin the car over. CC lights up normal, all functions visible. Make sure the A/C is OFF, then start the car. Let it idle for 10 sec., then push A/C button. Within 2-4 sec. the fuse blows and CC goes blank and no functions visible on CC and no buttons work. Issue is SOMEWHERE, SOMETHING, is grounding out.
Investigation: Began tracing wires from the TEMP button on the center console from the backside of the console. Thought TEMP switch (above radio ON button) was bad, bought one from a member here (Thanks SC300jz!!). NO CHANGE, fuse still blows when A/C turned on. Followed wires to large grey plug on top of A/C compressor. Checked resistance on the side coming FROM the cabin, no problems apparent (nothing shorting to ground). Checked same on the other plug, no indication of a grounding problem. Figured my Clutch was out. Spent a couple hours looking (online) for a clutch for this compressor, no luck. Back out to look at compressor. See another single wire connection while tracing wires out of connection that I had just tested. It is a single wire and appears to be the power wire to engage the clutch. Can't get tester probes from Multi-Meter into the connection. I leave the plug un-connected, put in a new fuse, turn key but DON'T start car, turn A/C OFF, start car, wait 10 sec. then push A/C button..........fuse does NOT blow
. Of course, A/C does not come on, BUT the fuse did not blow. This says that there is a direct short in this piece of wire. After moving around the wire, I see EXPOSED WIRING!!!!!. Upon further investigation, there are TWO wires, one a power wire to activate the compressor clutch, and a ground wire to complete the circuit. I separate the exposed wires, make sure they are not touching (grounding) anywhere, put in a new fuse, turn key but do not start car, turn off A/C using the CC, start car, idle for 10 sec., push A/C button on CC.....A/C IS WORKING
. The ENTIRE Problem was the wiring powering the compressor clutch had degraded (leaking Power Steering unit directly above) had broken down the rubber and exposed the wiring.Fix: Removed the power steering pulley (splined and wiggled off slowly) to have better access, and removed the wire loop holding the wires. This wire loop is VERY important. It supports one of the two pieces that make the electrical connection. It MUST be put back in place so that if you need to UNCLAMP the connection at a later date, it will stay in place. Went to Advance Auto and bought liquid electrical tape (yes, they do make this) and taped over, then applied liquid tape. Let dry (30 minutes). While putting everything back together, idler pulley bolt strips. Quick trip BACK to A/A for new idler, install, start car and A/C is ROCKING!!!!!!
Cliff Notes: Continually blowing HTR fuse when turning on A/C. This would blank out Climate Control, no buttons worked, no power. Traced problem to a bad power wire to A/C compressor clutch. Wire right at compressor had degraded and frayed because of age and leaking P/S fluid at some point in this cars life, grounding out and blowing fuse. Fixed wire (very difficult to get to) and A/C is back to normal. Climate Control functions normally also.
Jim
Last edited by Lexusdad; 05-15-11 at 07:10 PM.
05-30-11, 08:21 PM
#2
Bump for possible a/c problem fix for other owners.
Sorry for the self bump, but I spent FOREVER finding and fixing this. I was actually right by it several times, but could not see the frayed/bare wire grounding out. Hope this helps someone.
Jim
Sorry for the self bump, but I spent FOREVER finding and fixing this. I was actually right by it several times, but could not see the frayed/bare wire grounding out. Hope this helps someone.
Jim
07-23-11, 10:14 AM
#4
Jim
Very nice! A long time ago, I had an A/C related problem, the problem was my fender well harness on the driver side.
Every time I used my A/C there was chance it would engage the starter! After a long time, and the infamous hit-a-dip-and-headlights-and-wipers-come-on syndrome, I realized what was going on.
Very nice! A long time ago, I had an A/C related problem, the problem was my fender well harness on the driver side.
Every time I used my A/C there was chance it would engage the starter! After a long time, and the infamous hit-a-dip-and-headlights-and-wipers-come-on syndrome, I realized what was going on.
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