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1993 Del sol. NEw compressor and dryer. Charge it up and neither compressor or condenser fan are geeting power. So far I isolated the main control unit or EMC?
Have you checked the fuse (underhood fuse box) and the relays (on the radiator support near the condenser)?
The system uses negative logic. When the A/C button is pressed the stuff inside the car grounds the wire to the pressure switch, which starts the condenser fan and (if the pressure is OK) signals the ECU to turn on the compressor.
Thank you for getting back to me. I replaced the compressor and dryer. I charged The system with 18 onz if R134 after I retrofited. Pressure switch and ac thermostat has continuity. I tested both relay and they both work. Still neither compressor or condenser fan has power. I took it to AC shop and they say it could either be the control unit or the ECU. The control unit has been discontinued, so i want to find a way to bypass it or fix it. Im not very good with electric system, but I could figure things out. Trying to figure out what wires joint together through a switch I guess. I tested the both The fan and compressor from the battery and they both work. Thanks for any suggestions.
New Discovery. I disconnected the thermostat plug and when I was trying to measure power with my light tester everything started to work.what does that means?
when you disconnect a component and power returns to other components it usually means that that component or component circuit is shorting out the others.
I jumped the thermostat plug and it doesn't work.only works if I ground one of the two wires of the thermostat plug. When I do this, even if I turn off the ac from thecontrol unit, The compressor and fan continues to work. Any ideas.thank you sll for your ideas.
I have an EK, but I think the wiring is close enough.
I connected the blu/wht and blu/red wires from the thermostat together, just left the blk/yel (hot in ON) wire out, cut and spliced the 2 wires going to the switch on the drier, and spliced the compressor clutch coil wire through the switch on the drier.
Doing it this way will have the condenser fan always on when the A/C button is pressed, which means it won’t cycle on and off with the compressor; but the compressor will cut off if the system pressure builds too high or is too low.
I don't know about the Del Sol but the 5th generation Civic has a circuit board in the control panel which is prone to have cracked solder problems like a main relay. "Rebuilding" the control panel merely by resoldering may work.
The fan switch grounds the wire to the A/C button when the switch is in any position except off. When the fan is turned off, the ground is released which stops the A/C.
If the A/C button is pressed, the ground from the fan switch is linked to the thermo switch. Also through a separate circuit the light in the A/C button is turned on. As you can see, the light in the A/C button doesn't prove much about the system's health, but if it does come on that at least means you're getting the ground from the fan switch.
Don't hack up your wiring. This is not a complicated system to troubleshoot and repair properly.
Don't hack up your wiring. This is not a complicated system to troubleshoot and repair properly.
Way to be passive-aggressive... I suggested my solution as the OP had stated that a replacement thermostat is unavailable.
Anyway, to test whether the A/C thermostat is bad, unplug it and use a jumper wire to connect the terminals in the connector, start the car, and turn on the A/C. If everything comes on, your thermostat is faulty. If nothing happens, it may be the solder connection that mk378 mentioned.
I did a test with everything plug in and i ground the blue and red from behind the plug and everything works, except when I turn off the on and off switch, The system stays on for 5 or 10 seconds and then it shots off. What does that mean? Is the pressure switch turning the system off?can I add an independent switch to a new ground connected to the blue and red cable? Just my electric uneducated idea. Thanks guys.
If the condenser fan does not work or the system is badly overcharged, the pressure switch will turn it off after a few seconds.
Otherwise it should stay on until the evaporator gets cold enough (35 F) to turn off the thermo switch. Unless it is cold weather, that would take more than 5 seconds on the first run.
The two-wire thermo switches make an audible click inside the cabin when they turn off or on.
Yes you can just hold the blue-red wire to ground to make it work like the A/C button is pressed all the time.
The system is not over charged because I had a set of gauges and while running when I grounded the plugs, pressure were fine on both sides. My question is why when I turn off switch from the control unit,the compressor and fan stay on for for few seconds (5 to 10 seconds)
I need some ideas with my AC guys.Pressures are under normal limits like the chart says, I replaced the ac compressor and evaporator and the expansion valve. If I keep the AC fan low,it will cold down to 68 or so,but if I increase the fan speed the temperature will go to 80's. no sure if is a temperature blend door no allowing the cold air to come out, it feels cold underneath the gloves compartment. Any ideas. Thank you team.
04-28-2018, 07:55 AM
By passing AC climate control unit.
