My blower is working correctly, by blue AC switch lights when depressed, but compressor clutch is not engaging, nor is the idle advancing. The 10amp AC fuse is good so that's not the problem. I also do not believe it is the 30amp breaker as that also knocks out the fan and AC switch, and it appears to be set correctly. Is there a relay between the switch and the compressor and if so, where is it located. The AC was working fine this morning when I parked it, but would not engage this afternoon when I started the vehicle. I'm thinking its a circuit problem between the switch and the compressor. Any advice welcomed.
FJ60 AC Compressor Relay
- Thread starter dunnyboy
- Start date
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Check for voltage at the plug on the compressor with everything switched on - Should be 12v
If you have power at the compressor, possible clutch/comp issues.
If no power at compressor, run a jumper from battery to compressor and see if clutch engages. If yes start checking wire and electrics.
If these all work, it gets more complicated.
AC board
Idle up controller
Pressure switch
Maybe bad wire if no power at comp/
Doug
If you have power at the compressor, possible clutch/comp issues.
If no power at compressor, run a jumper from battery to compressor and see if clutch engages. If yes start checking wire and electrics.
If these all work, it gets more complicated.
AC board
Idle up controller
Pressure switch
Maybe bad wire if no power at comp/
Doug
- Thread starter
- #3
Doug,
Thanks for the advice. That's kind of what I was thinking. I'll check the power at the compressor in the morning and see if the circuit is good to that point. If not, I'll check at the output of the dash switch and see if it is functioning. I was trying to determine if the dash switch fed to a relay or other component on the circuit to the compressor.
When you say the AC board you are referring to what?
Thanks,
Scott
Thanks for the advice. That's kind of what I was thinking. I'll check the power at the compressor in the morning and see if the circuit is good to that point. If not, I'll check at the output of the dash switch and see if it is functioning. I was trying to determine if the dash switch fed to a relay or other component on the circuit to the compressor.
When you say the AC board you are referring to what?
Thanks,
Scott
There is a relay on the AC Amplifier, the board that's tucked into a pocket on the evaporator box under the dash on the passenger side. The dash switch triggers the relay, but only if RPMs are in the right range, AC system pressure is not too low or too high, and evaporator temp is not too low.
more AC
Will the compressor NOT come on if the system is not charged? I just changed all the seals but the comp will not power up. The comp came on before I started the seal change. There was pressure in the system but very little to speak of.
No power to the lead wire.
can jump comp from batt - does work.
Idle is not working.
I do hear the amplifier clicking.
Fuse ok at fuse box.
Will the compressor NOT come on if the system is not charged? I just changed all the seals but the comp will not power up. The comp came on before I started the seal change. There was pressure in the system but very little to speak of.
No power to the lead wire.
can jump comp from batt - does work.
Idle is not working.
I do hear the amplifier clicking.
Fuse ok at fuse box.
Just debugging some AC issues, so thought I would add value to an old thread.
AC compressor does appear to come on when on when no gas pressure. FJ62 3F. I'm sure the gas is empty as I can press on both high-low side AC valves and no gas comes out.
I removed the power lead going to the AC compressor (its near battery on mine (Australian FJ62). Plug in a meter and the voltage is bouncing arround 0.5V up to 3 V, with our without the AC turned on.
However, when I increase the Revs (1200rpm), the AC button now creates a voltage 12V at the plug, with AC on and 2-4V fluctuating with it off.
When I Connect the power lead back to the compressor the compressor is kicking in and I can see the outside ring now spinning. So,
- ignore the fluctuating voltages
- need 12V at the AC power lead for it to engage.
Now to investigate where the Gas went. Hasnt worked since Previous Owner.
AC compressor does appear to come on when on when no gas pressure. FJ62 3F. I'm sure the gas is empty as I can press on both high-low side AC valves and no gas comes out.
I removed the power lead going to the AC compressor (its near battery on mine (Australian FJ62). Plug in a meter and the voltage is bouncing arround 0.5V up to 3 V, with our without the AC turned on.
However, when I increase the Revs (1200rpm), the AC button now creates a voltage 12V at the plug, with AC on and 2-4V fluctuating with it off.
When I Connect the power lead back to the compressor the compressor is kicking in and I can see the outside ring now spinning. So,
- ignore the fluctuating voltages
- need 12V at the AC power lead for it to engage.
Now to investigate where the Gas went. Hasnt worked since Previous Owner.
I am having the exact same problem with my 83 FJ60. I took out switch and tested, jumped compressor to battery and it works, voltage at compressor plug jumping around at low voltage. What ended up being the solution for you?
Ignore the "voltage at compressor plug jumping around at low voltage".. measurements with a high impedance digital voltmeter are meaningless in these scenarios. A test lamp is your best tool.
The compressor trigger wire provides 12V+ provided:
- Ignition is on
- A/C Blue Switch is on
- Blower Motor is on
- Pressure switch is happy (system is gassed)
- Thermistor and the "A/C Amplifier" determine the temperature of the system demands the compressor come on.
The "A/C amplifier" is a small PCB located on the front of your heater enclosure in the cab - in front of your gear stick.
. delete.
I found on another site how I can solder a jumper on the control board. I did this and at least the AC comes on when I press the button. It lacks the pressure I would want and will have to dump some refrigerant into it, but that is life. Bigger fish to fry on this thing
