Elantra with no A/C
#1
07-04-2012, 04:54 PM
Elantra with no A/C
I’ve got a 2000 Hyundai Elantra sedan with 126,000 miles. Prior to this problem, everything worked normally.
The heater/ac blower threw its windings and locked up with a dead short. Burned out the resistor unit and the 30 amp fuse link when it went. I replaced the blower motor, resistor and fuse link and got the blower to run OK, but now the compressor won't come on. I jumpered to the A/C clutch and the clutch is OK and there is enough refrigerant in the system. The radiator fan does not come on when A/C is selected but does run when engine temp needs control. I have none of the indicator lights on the push buttons that control the A/C. Also as soon as I turn on the fan switch, the indicator for the rear defrost comes on but the rear defrost doesn’t work. Somewhere along the way I also got a full time air bag indicator on the dash. The circuit thru the fan switch checks out OK. All the ground circuits are visually OK. There is no visual damage on any of the wiring. I also replaced the 2 A/C relays in the power box under the hood. All other fuses are OK. Something strange is that when I hold the rear defrost button in, the A/C compressor runs as long as I hold the button in. As soon as I release it the A/C stops.
Perhaps a related problem, which started shortly before the A/C problem, I have a recurring P0131 engine code (insufficient voltage to the oxygen sensor). I reset it and it stays off for a few days to a month and then comes back on. Some mice chewed off the wiring to the oxygen sensor a few months ago. I replaced the wiring with a section from a salvage vehicle and soldered the new connections. I've also replaced the oxygen sensor.
I know that some of the circuitry for the A/C, rear defrost, and air bag goes thru the ECU. I replaced the ECU and the switches on the center console, but that did not fix these problems either. I also on the advice of a friend replaced the timing module that is under the center dash. This is the unit often referred to as the lock/anti-theft module.
Car runs OK except for these problems.
The heater/ac blower threw its windings and locked up with a dead short. Burned out the resistor unit and the 30 amp fuse link when it went. I replaced the blower motor, resistor and fuse link and got the blower to run OK, but now the compressor won't come on. I jumpered to the A/C clutch and the clutch is OK and there is enough refrigerant in the system. The radiator fan does not come on when A/C is selected but does run when engine temp needs control. I have none of the indicator lights on the push buttons that control the A/C. Also as soon as I turn on the fan switch, the indicator for the rear defrost comes on but the rear defrost doesn’t work. Somewhere along the way I also got a full time air bag indicator on the dash. The circuit thru the fan switch checks out OK. All the ground circuits are visually OK. There is no visual damage on any of the wiring. I also replaced the 2 A/C relays in the power box under the hood. All other fuses are OK. Something strange is that when I hold the rear defrost button in, the A/C compressor runs as long as I hold the button in. As soon as I release it the A/C stops.
Perhaps a related problem, which started shortly before the A/C problem, I have a recurring P0131 engine code (insufficient voltage to the oxygen sensor). I reset it and it stays off for a few days to a month and then comes back on. Some mice chewed off the wiring to the oxygen sensor a few months ago. I replaced the wiring with a section from a salvage vehicle and soldered the new connections. I've also replaced the oxygen sensor.
I know that some of the circuitry for the A/C, rear defrost, and air bag goes thru the ECU. I replaced the ECU and the switches on the center console, but that did not fix these problems either. I also on the advice of a friend replaced the timing module that is under the center dash. This is the unit often referred to as the lock/anti-theft module.
Car runs OK except for these problems.
