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| AIr Conditioning / Compressor Switches ... I screwed up. (Page 1/2) |
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82-T/A [At Work]
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AUG 03, 06:55 PM
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Ok, so... I'm converting to a V5 compressor... to get rid of the HR6 compressor in my 1985 Fiero.
HOWEVER... I accidentally recycled my old HR6 compressor, without saving the compressor switches.
I know the V5 also has two switches in the back... can anyone tell me what switches I need to get for the V5, and... if the old HR6 switches will fit in there, AND... where I can get new HR6 sensors?
I know there's something else I need to do... but basically... I don't have any sensors for my compressor... ugh... and they don't seem to sell replacement original ones.
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cartercarbaficionado
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AUG 03, 08:47 PM
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| quote | Originally posted by 82-T/A [At Work]:
Ok, so... I'm converting to a V5 compressor... to get rid of the HR6 compressor in my 1985 Fiero.
HOWEVER... I accidentally recycled my old HR6 compressor, without saving the compressor switches.
I know the V5 also has two switches in the back... can anyone tell me what switches I need to get for the V5, and... if the old HR6 switches will fit in there, AND... where I can get new HR6 sensors?
I know there's something else I need to do... but basically... I don't have any sensors for my compressor... ugh... and they don't seem to sell replacement original ones. |
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I think rockauto has some still. maybe the fiero store? honestly though that was a bit of an oversight.
I do have some r134a switches out of a 1995 gtp so see what compressor it uses since those are known good
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Vintage-Nut
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AUG 03, 10:07 PM
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82-T/A [At Work]
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AUG 04, 09:08 AM
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Yeah... I just really didn't want to have to go that direction. Are there no older sensors left?
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RWDPLZ
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AUG 05, 12:22 AM
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The old style switches were impossible to find even back in 2011, the supply has long since dried up.
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82-T/A [At Work]
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AUG 05, 07:43 AM
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| quote | Originally posted by RWDPLZ:
The old style switches were impossible to find even back in 2011, the supply has long since dried up. |
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Alright... I guess it's what it is... haha... thanks. Your write-up in that linked post is really good. I appreciate the information.
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ceverhart
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AUG 05, 09:39 PM
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Popping in to say thanks to RWDPLZ!
I am replacing an ac compressor and broke the mushroom piece on the switch coming out.....your info saved me tons of time.....
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82-T/A [At Work]
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SEP 07, 04:39 PM
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I don't want to create a new thread, since I already created this one, and no point in creating MULTIPLE threads (which I've already done, but don't want to make it worse, and I'll update all the dumb threads I've created once I figure this out).
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Long and short, this is for my daughter's Fiero. 1985 Fiero 2m4 SE. It had the DA6 compressor, and I was able to use all the brackets from a 1988 to get the V5 compressor to fit.
I was able to find a set of usable 1987 Fiero 4cyl Coupe A/C lines from The Fiero Farm (thank you!):
The pair on the left is the original from my daughter's 1985, which connects the factory body-lines to a DA6.
The pair on the right is the new one from a 1987 Fiero Coupe (4cyl), which connects the factory body-lines to a V5 compressor.
Note, the biggest issue with the DA6 is that the pressure and return line holes are REVERSED. The 87 line set fixes this for me, as you'll see if you look carefully. It allows the V5 compressor to correctly mate to the factory line, which are unchanged at least from this 1985 2m4 SE, and the 1987 donor car that this came from. The mounts are the same.
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:
... which now brings me to the A/C switches.
Ok, I'm not a big fan of taking no for an answer, so I used Maltego (a hacking tool) to scour the internet for me looking for both the original RED and WHITE switches that were original on the Fiero. I ordered three original sets from different places... and this is what has arrived so far.
Now, I still need to figure out what switch goes where, but here's what I understand:
- The low-pressure switch is the "white mushroom" original switch.
- The high-pressure switch is the "red pintle" style original switch.
Here's where I'm confused, and I'm not finding what I need.
WHAT SENSORS DO I NEED TO UPGRADE TO A V5 COMPRESSOR?
This is a quick diagram I made (based on what I've read about the V5 compressor in the 1986 Fiero Service Manual) on where the low and high side pressure switches go:
OK, NOW... from what I can gather... both of them are "pressure switches" and it doesn't really matter at all which sensor goes where, because the pressure is equal in both of those locations. So... point being, if you had a low pressure switch, it would be fine in there, same as a high pressure switch would.
SO... with that in mind, here are three questions that I can't seem to answer:
- Can I simply just install the original White Mushroom and Red Pintle switches into the V5 compressor and be done with it?
- What do I do with the "cycle switch" that's in the front compartment? Does this even need to do anything at this point?
- Biggest issue that just occured to me. Is the V5 compressor made of aluminum? Or is that steel? These are 1-lead sensors, and if they need a ground, and the compressor is aluminum, then it's not making a ground?
Would really appreciate any help guys... thank you!!!
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RWDPLZ
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SEP 07, 09:56 PM
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| quote | Originally posted by 82-T/A [At Work]:
SO... with that in mind, here are three questions that I can't seem to answer:
- Can I simply just install the original White Mushroom and Red Pintle switches into the V5 compressor and be done with it?
- What do I do with the "cycle switch" that's in the front compartment? Does this even need to do anything at this point?
- Biggest issue that just occured to me. Is the V5 compressor made of aluminum? Or is that steel? These are 1-lead sensors, and if they need a ground, and the compressor is aluminum, then it's not making a ground?
Would really appreciate any help guys... thank you!!!
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Here's the problem:
The DA6/HR6 is active when the cycling switch in the front compartment turns it on, and turns off when the cycling switch turns it off (clutch engaged or clutch disengaged).
The V5 compressor is a variable displacement compressor that varies output based on the control valve in the compressor body. Clutch is on when computer signals it on.
The red and white switches (high pressure cut-out and fan switch) are safety devices, designed more to protect the car and its components than anything else. The red switch cuts off if pressure is too high, and the fan switch keeps the fan on as long as the AC is on and pressures are elevated, to keep air moving across the condenser if the normal fan switch fails.
The switches on the V5 compressor are high and low pressure cut offs: The high pressure switch switch cuts off if pressure is too high, and the low pressure switch cuts off if pressure is too low.
What you're building is a hybrid system, a variable compressor in what is otherwise the original 'clutch slapper' type system. In theory, the best way to get this to work would be to use a computer from an 86-88 4 cylinder Fiero that had a V5 compressor from the factory, but there are likely other wiring changes that need to be checked and accounted for if installing it in an older car.
By far the easiest solution is just to buy the HR6 compressor to put in the 85.
| quote |
- Can I simply just install the original White Mushroom and Red Pintle switches into the V5 compressor and be done with it?
- What do I do with the "cycle switch" that's in the front compartment? Does this even need to do anything at this point?
- Biggest issue that just occured to me. Is the V5 compressor made of aluminum? Or is that steel? These are 1-lead sensors, and if they need a ground, and the compressor is aluminum, then it's not making a ground? |
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-No, V5 compressor low pressure cut-off switch functions at far lower pressure than the DA6/HR6 fan switch (V5 compressor switch ON 30psi, OFF 29psi, DA6/HR6 compressor switch ON 250psi, OFF 160psi). Red switches serve the same function.
-Would need to be bypassed somehow, variable displacement compressor doesn't use it.
-Aluminum is metal, and conducts electricity just fine. DA6 and HR6 were also aluminum. If the rest of the grounds are good, it will function fine with 1 wire switches.[This message has been edited by RWDPLZ (edited 09-07-2024).]
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82-T/A [At Work]
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SEP 08, 09:27 AM
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| quote | Originally posted by RWDPLZ:
-No, V5 compressor low pressure cut-off switch functions at far lower pressure than the DA6/HR6 fan switch (V5 compressor switch ON 30psi, OFF 29psi, DA6/HR6 compressor switch ON 250psi, OFF 160psi). Red switches serve the same function.
-Would need to be bypassed somehow, variable displacement compressor doesn't use it.
-Aluminum is metal, and conducts electricity just fine. DA6 and HR6 were also aluminum. If the rest of the grounds are good, it will function fine with 1 wire switches.
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Thank you RWDPLZ! I appreciate it. So, my thoughts here are:
- The DA6/HR6 use significantly lower pressure switches. 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?) 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?
- 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?
- RGR, good to know, thank you! I forget that 1970s homes used aluminum wiring too. I guess I confused myself, knowing that it's not ferrous, that somehow it also wasn't conductive, lol.
EDIT: Just found an ECM for $27 shipped, that has the correct PROM (FAU2975) that I need for my car... which is an 86 Fiero 2m4 SE w/ 5-speed and V5 compressor. The ECM itself is identical to mine (same ECM number, 1226864), so all I'll need to do is swap out the PROM.
I have both an 85 manual and an 86 manual, so I'll compare the wiring diagrams and see what the difference really is. Thanks![This message has been edited by 82-T/A [At Work] (edited 09-08-2024).]
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