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| AIr Conditioning / Compressor Switches ... I screwed up. (Page 2/3) |
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fierofool
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SEP 08, 10:13 AM
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Something to note. It doesn't matter in which port the high and low pressure switches are installed. They both sense pressures from the same internal chamber.
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RWDPLZ
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SEP 08, 10:22 AM
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| quote | Originally posted by 82-T/A [At Work]:
Thank you RWDPLZ! I appreciate it. So, my thoughts here are:
- The DA6/HR6 use significantly lower pressure switches.
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No, significantly higher pressure switches, in the compressor. The cycling switch turns the compressor off when it gets down to 25psi on R-12, or 21psi on R-134A.
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And the LOW pressure switch, of course, is to ensure that the compressor doesn't continue to run if it's completely run out of freon (and oil... more specifically?)
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Out of refrigerant, or prevents the system from going into a vacuum and imploding. The refrigerant controls actually don't care how much oil is in the system.
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Or are you saying that the pressures are the same, and RED switch can STILL be used in this case... just that the low-pressure switch goes on / off at lower pressures?
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The high pressure switches are the same between the DA6/HR6 and V5, and serve the same function, to turn the system off if over-pressurized.
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- Based on what I think you're saying... if I'm not mistaken, I can literally just keep it looking stock (the cycle switch), and just permanently ground out (or disconnect) the harness?
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While you CAN run the A/C system without the switches, they are safety devices, and bypassing a safety device is NOT a good idea. Unless you're referring to the cycling switch on the accumulator, in which case you could keep it on the accumulator if you wanted to? It would need to be bypassed or disconnected to use the V5 compressor.
| quote | Originally posted by fierofool:
Something to note. It doesn't matter in which port the high and low pressure switches are installed. They both sense pressures from the same internal chamber.
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True, the wiring is also long enough the connectors can reach either port.[This message has been edited by RWDPLZ (edited 09-08-2024).]
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82-T/A [At Work]
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SEP 08, 01:12 PM
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| quote | Originally posted by RWDPLZ:
Lots of info...
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Ok, so I think I understand everything.
Here's what I've done (and again, thank you so much for helping me with this).
- I installed the RED factory original style high-pressure switch, and will continue to use that.
- I have disabled the cycling switch.
I now have two problems:
- How do I make sure the fan turns on in AC mode? ...since I cannot use the original (white mushroom style) low pressure switch. It seems like the fan gets turned on automatically by the control head when you turn it to Air Conditioning... but does NOT when you are using the defrost option (that I saw from another thread).
- What color LOW PRESSURE SWITCH should I install in the other port? And... can this also be used to control the fan?
Thank you so much!!!
I intend to update my other thread and include all this information.
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RWDPLZ
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SEP 08, 01:54 PM
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| quote | Originally posted by 82-T/A [At Work]:
- How do I make sure the fan turns on in AC mode? ...since I cannot use the original (white mushroom style) low pressure switch. It seems like the fan gets turned on automatically by the control head when you turn it to Air Conditioning... but does NOT when you are using the defrost option (that I saw from another thread).
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Correct, the fan turns on in the NORMAL, MAX or B/L A/C modes. The switch on the DA6/HR6 compressor is actually redundant fail safe (if you were running the A/C on a hot day and pressures are high, and you suddenly switched the A/C off or into defrost mode, the fan would continue to run until system pressure got down to 160psi).
(couldn't find a newer diagram)
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- What color LOW PRESSURE SWITCH should I install in the other port? And... can this also be used to control the fan?
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THAT I'm not sure, I've never worked on a V5 car, and the whole point of the threads 10 years ago was to actually document what wasn't out there already. The old switches were no longer available (through conventional means anyway, not including checking dusty old shelves for inventory long forgotten), so I never bothered trying to find the original part numbers. Switch color may not even be indicative of the switch properties, they might both be white. If anyone with a nice original 86-88 4 cylinder could check, that would be great.
The low pressure switch on the V5 systems does operate the fan indirectly, in the opposite way the DA6/HR6 system does: Normally its just a safety to turn the A/C off below 8PSI (the modern switch is 29psi, the closest currently available equivalent).
Although shown in the same location in the diagram, the V5 low and high pressure switches don't perform the same function as the DA6/HR6 cycling switch: Rather they use the same input pin on the ECM. The V5 system also uses the fan control pin on the ECM to CUT the fan if pressures are too low (if pressure is too low, you'd actually want to warm up the condenser to increase pressure).
In order to use the V5 compressor in the DA6/HR6 car, you'd want to cut the signal wire to the cycling switch, and run new wires from that ECM pin to the switches on the compressor, wired in the same way. Note the locations of the C100 and C203 main connectors in the diagram in relation to the switches.
Again, I'd just put an HR6 compressor in the car and be done with it, far simpler and cheaper solution.[This message has been edited by RWDPLZ (edited 09-08-2024).]
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RWDPLZ
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SEP 08, 02:17 PM
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| quote | Originally posted by 82-T/A [At Work]:
Next challenge is actually mounting the 87 line to the compressor. I ordered a brand new V5 compressor from Four Seaons, which makes high quality compressors. The problem is that the mount on the compressor has changed slightly, and there's a "puzzle" of sorts using different gaskets and spares to properly seat the lines at the compressor junction. Four Seasons uses the "lowest common denominator" approach, and thus creates a bunch of different sized gaskets to allow their single design V5 to work with everything else.
This is effectively the chart that I found:
And best I can figure at this point, this is my combination that I need to use:
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Also to address this point from earlier:
Assuming your hose assembly mating face looks like this:
You want to use the green and red washers, and nothing else, with the green washer in the deeper hole.
I don't know WHY they did this, the original o-ring design was much better and simpler, maybe some patent troll shenanigans?
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Romsk
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JUN 05, 08:54 AM
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Great thread!
As Fiero parts get harder and harder to find, I find myself comming up with my own designs of aftermarket solutions.
For example, if I had specs (and the pressure switches in front of me), I am sure I can have parts made to replace them. They are just a diaphragm, spring, and an electrical contact.
The EGR Solenoid is now very hard to get. I have a design in the queue to make these affordable and available again.
I already make the ALDL Monitor GUI and Adapter, the "Paperclip" Adapter, and the Rear Trunk LED Lamp with Switch products.
I think I have found a market making aftermarket replacements for many discontinued Fiero parts. Could I design a brake caliper? Yes, I could, but hydraulics is not my forte.
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Dennis LaGrua
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JUN 05, 10:42 AM
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You may be able to use a compressor without pressure switches. The one on my 3800Sc swap doesn't have any. . Instead we brazed a high pressure switch/port onto the high side line and the low pressure switch remains on the receiver dryer/accumulator under the hood. A/C control is done by the PCM in this instance but you can probably use the Fiero control scenario with external switches. Costly using a compressor without the switches but in view of the shortage of parts this may be an alternative. ------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "
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Brian A
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JUN 05, 04:59 PM
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I have a related question:
I am simply replacing my HR6 compressor. The two switches came out fine. They look original. Are they prone to failure? Can I just reuse them? Can I test them somehow?
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82-T/A [At Work]
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JUN 05, 05:07 PM
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| quote | Originally posted by Brian A:
I have a related question:
I am simply replacing my HR6 compressor. The two switches came out fine. They look original. Are they prone to failure? Can I just reuse them? Can I test them somehow? |
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Those switches rarely "fail" but they often break... like the mushroom connector breaks off, etc. So, if they're in good shape, you can totally re-use them.
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fierofool
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JUN 12, 11:07 AM
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| quote | Originally posted by Romsk:
Great thread!
As Fiero parts get harder and harder to find, I find myself comming up with my own designs of aftermarket solutions.
For example, if I had specs (and the pressure switches in front of me), I am sure I can have parts made to replace them. They are just a diaphragm, spring, and an electrical contact.
The EGR Solenoid is now very hard to get. I have a design in the queue to make these affordable and available again.
I already make the ALDL Monitor GUI and Adapter, the "Paperclip" Adapter, and the Rear Trunk LED Lamp with Switch products.
I think I have found a market making aftermarket replacements for many discontinued Fiero parts. Could I design a brake caliper? Yes, I could, but hydraulics is not my forte. |
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So, do we use the insert with the green O-ring shown sitting on the compressor, or not. Is it used in any form? Or is it just the green and red seals that come in the kit?
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