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#1
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A/c completely dead, need advice
Hey all,
Car is a 1986 Honda CRX. Where should I start looking for trouble if pushing the A/C button does _nothing_? No increased idle, no condenser fan, and obviously no cooling. the only thing that happens is the little "A/C" light turns on. Thanks James |
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#2
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A/c completely dead, need advice
Masospaghetti wrote:
> > Hey all, > > Car is a 1986 Honda CRX. Where should I start looking for trouble if > pushing the A/C button does _nothing_? No increased idle, no condenser > fan, and obviously no cooling. the only thing that happens is the little > "A/C" light turns on. > > Thanks > James Take it to a reputable shop, or buy a service manual. Might want to spend the $15 on a service manual first anyway so you can check the simpler stuff yourself. Either way, if the system needs evac and recharge you're going to need to bring it to a shop for that due to freon regulations. I recently repaired the A/C on my truck. I took it to a shop for diagnosis which revealed leaking compressor seals. I couldn't justify the cost to replace with new for a 9yr old truck so I had them leave the system empty. I then replaced the compressor, orifice tube and accumulator dryer myself using inexpensive rebuilt parts. Once I was done I brought the truck back to the shop for evac and recharge. The A/C is now working fine and I saved quite a bit of money. Of course you can't expect the shop to warranty anything other than their refrigerant charge, but considering the money saved I could do all the same again and still be ahead. Pete C. |
#3
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A/c completely dead, need advice
Pete C. wrote: > Masospaghetti wrote: > > > > Hey all, > > > > Car is a 1986 Honda CRX. Where should I start looking for trouble if > > pushing the A/C button does _nothing_? No increased idle, no condenser > > fan, and obviously no cooling. the only thing that happens is the little > > "A/C" light turns on. > > > > Thanks > > James Most likely due to an empty system. The low pressure switch is preventing the clutch from engaging. To diagnose, find the LPS on the accumulator and jumper the connection while the a/c is on. If the clutch kicks in, that is the problem. Don't run it for long. Just verify the clutch kicks in. If the clutch does not engage, you have other problems. Get a manual and a DVM and start tracing. With an old R-12 system, it will probably not be cost effective to get it fixed and charged with R-12. What I would recommend, providing you have the tools, is to convert to R-134. First you need to figure out where the R-12 leaked out. Most likely on the high pressure(hot side) of the compressor. Probably the crimp right next to the compressor. Replace whatever is leaking. Replace all of the o-rings in the system. Replace the orifice tube. Replace the accumulator. Drain all of the oil you can out of the hoses/system. You can get little adapter ports to change the R-12 ports to R-134. Get those and screw onto your existing ports. Fill the system with the recommended amount of PAG oil(it will say on the compressor). Seal the sytem up. Evacuate the system(requires a vacuum pump). Charge with 80% of the recommended charge for R-12 with R-134a. Enjoy the cold. |
#4
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A/c completely dead, need advice
Masospaghetti wrote: > Hey all, > > Car is a 1986 Honda CRX. Where should I start looking for trouble if > pushing the A/C button does _nothing_? No increased idle, no condenser > fan, and obviously no cooling. the only thing that happens is the little > "A/C" light turns on. > > Thanks > James Suggest that you take the car to a dealer and have them fix the car. |
#5
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A/c completely dead, need advice
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#7
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A/c completely dead, need advice
I just wanted to know what could cause the system to be _completely_
dead, because usually the fans at least turn on. I tried posting about a week ago with a hugely long description and didn't get a single response. i've gone through and tested the following components, which tested OK: low pressure switch a/c thermostat a/c delay timer a/c relay clutch relay a/c clutch a/c diode radiator fan relay a/c switch none of the relays are even getting a signal. is there some control box that the button goes to that might be bad? Thanks -James John S. wrote: > Is there some reason you didn't include this in the first message? The > first message reads like someone who knows nothing about cars. > > > Masospaghetti wrote: >> wrote: >>> Pete C. wrote: >>>> Masospaghetti wrote: >>>>> Hey all, >>>>> >>>>> Car is a 1986 Honda CRX. Where should I start looking for trouble if >>>>> pushing the A/C button does _nothing_? No increased idle, no condenser >>>>> fan, and obviously no cooling. the only thing that happens is the little >>>>> "A/C" light turns on. >>>>> >>>>> Thanks >>>>> James >>> Most likely due to an empty system. The low pressure switch is >>> preventing the clutch from engaging. >> The system has plenty of refrigerant. I would have expected that the at >> least the condenser fan and boosted idle to kick in if it was just low >> on refrigerant. >> >> I tried jumping the clutch relay and the compressor engages. the system >> actually cools extremely well. >> >> I figured it would be low refrigerant when I first saw the car too, but >> I pushed on the low-side schrader and got a huge blast coming out. >> >>> To diagnose, find the LPS on the accumulator and jumper the connection >>> while the a/c is on. If the clutch kicks in, that is the problem. >>> Don't run it for long. Just verify the clutch kicks in. If the clutch >>> does not engage, you have other problems. Get a manual and a DVM and >>> start tracing. >>> >>> With an old R-12 system, it will probably not be cost effective to get >>> it fixed and charged with R-12. >>> >>> What I would recommend, providing you have the tools, is to convert to >>> R-134. >>> >>> First you need to figure out where the R-12 leaked out. Most likely on >>> the high pressure(hot side) of the compressor. Probably the crimp >>> right next to the compressor. >>> >>> Replace whatever is leaking. Replace all of the o-rings in the system. >>> Replace the orifice tube. Replace the accumulator. >>> >>> Drain all of the oil you can out of the hoses/system. >>> >>> You can get little adapter ports to change the R-12 ports to R-134. >>> Get those and screw onto your existing ports. >>> >>> Fill the system with the recommended amount of PAG oil(it will say on >>> the compressor). >>> >>> Seal the sytem up. Evacuate the system(requires a vacuum pump). >>> >>> Charge with 80% of the recommended charge for R-12 with R-134a. >>> >>> Enjoy the cold. >>> >> thanks for the advice. > |
#8
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A/c completely dead, need advice
Masospaghetti wrote:
> > I just wanted to know what could cause the system to be _completely_ > dead, because usually the fans at least turn on. I tried posting about a > week ago with a hugely long description and didn't get a single response. > > i've gone through and tested the following components, which tested OK: > > low pressure switch > a/c thermostat > a/c delay timer > a/c relay > clutch relay > a/c clutch > a/c diode > radiator fan relay > a/c switch > > none of the relays are even getting a signal. is there some control box > that the button goes to that might be bad? > > Thanks > -James In at least some vehicles the A/C command from the dash switch routes through the ECM and then to the A/C compressor clutch relay. This allows the ECM to disengage the A/C clutch momentarily during hard acceleration / high engine load to recover the HP used by the A/C compressor and give better performance. You could have a failed connection in wiring to / from the ECM, or you could potentially have a blown output on the ECM which could be and ECM failure itself, or be caused by a short circuit further downstream that could kill another ECM output if the ECM is replaced without resolving the real problem. Again a factory wiring diagram or at least a look at one to collect the relevant information would be a big help here. Pete C. |
#9
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A/c completely dead, need advice
"Pete C." > wrote in message ... > Masospaghetti wrote: > > > > Hey all, > > > > Car is a 1986 Honda CRX. Where should I start looking for trouble if > > pushing the A/C button does _nothing_? No increased idle, no condenser > > fan, and obviously no cooling. the only thing that happens is the little > > "A/C" light turns on. > > > > Thanks > > James > > Take it to a reputable shop, or buy a service manual. Might want to > spend the $15 on a service manual first anyway so you can check the > simpler stuff yourself. Either way, if the system needs evac and > recharge you're going to need to bring it to a shop for that due to > freon regulations. > > I recently repaired the A/C on my truck. I took it to a shop for > diagnosis which revealed leaking compressor seals. I couldn't justify > the cost to replace with new for a 9yr old truck so I had them leave the > system empty. I then replaced the compressor, orifice tube and > accumulator dryer myself using inexpensive rebuilt parts. Once I was > done I brought the truck back to the shop for evac and recharge. > I've done this myself before, however I have a leak detector, vacuum pump and guage set, flush gun and can do everything without paying a shop. Keep in mind that if you get 2 years out of an inexpensive rebuilt compressor, your doing pretty good. Ted |
#10
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A/c completely dead, need advice
Ted Mittelstaedt wrote:
> > "Pete C." > wrote in message > ... > > Masospaghetti wrote: > > > > > > Hey all, > > > > > > Car is a 1986 Honda CRX. Where should I start looking for trouble if > > > pushing the A/C button does _nothing_? No increased idle, no condenser > > > fan, and obviously no cooling. the only thing that happens is the little > > > "A/C" light turns on. > > > > > > Thanks > > > James > > > > Take it to a reputable shop, or buy a service manual. Might want to > > spend the $15 on a service manual first anyway so you can check the > > simpler stuff yourself. Either way, if the system needs evac and > > recharge you're going to need to bring it to a shop for that due to > > freon regulations. > > > > I recently repaired the A/C on my truck. I took it to a shop for > > diagnosis which revealed leaking compressor seals. I couldn't justify > > the cost to replace with new for a 9yr old truck so I had them leave the > > system empty. I then replaced the compressor, orifice tube and > > accumulator dryer myself using inexpensive rebuilt parts. Once I was > > done I brought the truck back to the shop for evac and recharge. > > > > I've done this myself before, however I have a leak detector, vacuum > pump and guage set, flush gun and can do everything without paying a > shop. Keep in mind that if you get 2 years out of an inexpensive rebuilt > compressor, your doing pretty good. > > Ted Do you also have a refrigerant recovery / recycling unit and EPA cert. for refrigerant? I can't justify the time / money / effort for those given the couple times a decade I might use them. Easier to have the shop recover, I do the work on the empty system and then have them evac and recharge. Pete C. |
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