A/C troubleshooting

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Briano1234
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Re: A/C troubleshooting

Post by Briano1234 »

Just run a new wire through one of the existing feed throughs that are at the top of the dash What I so is to disconnect the battery, then in the large connector bundle next to the drivers side strut tower, use a wire coat hanger and push it through then tape the new wire to it, then pull it through from the inside.

After you get it pulled through, then seal the bundle back up with RTV. You don't have to run it through the vinyl tube, but you can run it along side.
Briano

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GreenCabbie
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Re: A/C troubleshooting

Post by GreenCabbie »

If I thought I was done I wasn't!!!

I traced the supply side wire of S23 out to the battery and to make this project even more perplexing , the wire was connected to the negative terminal of the battery. I am the 4 th or 5th owner of this car. So no telling how long it has been like that. So I toned it out to make sure and tested it for any short circuit to ground. Then moved it over to the postive terminal. Turned on the key and the Hi Speed Blower fan and the clutch engaged .

All was good, I thought. Since I could not find a thermofuse , I put in a regular 30 amp fuse. And while it was in the garage idling the 30 amp regular fuse held.

Then I took for a test drive and 30 amp regular fuse blew? No Hi speed fan or ac clutch. No ac relay .

So I put in another 30 amp fuse and lessened the load by not using the hi speed of the blower. I just used the ac compressor and it stayed on and ran.

Do you think a thermofuse will solve this to where I can run the blower and the compressor at the same time? Do you know where I can find some of those thermofuses?

After running the ac compressor I got very little cooling! I attached my multigages to the Low Pressure side and measured 50 psi and the high pressure side and measured 230 psi.

These numbers tell me very little as what to do next to get better cooling. Any ideas would be appreciated. Recall I did put in a new heater control valve.

Thanks
Green Cabbie
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Briano1234
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Re: A/C troubleshooting

Post by Briano1234 »

Yes you need the thermo-fuse.

That means that your compressor is running, but I would suspect that you have a need to put some gas in it.
If your heater valve isn't fully shut, then you can bleed off a/c air over the heated core from the center vents.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:
GreenCabbie
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Joined: Wed Jul 18, 2012 11:17 pm
What year is your cabby?: 1992
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Re: A/C troubleshooting

Post by GreenCabbie »

So I understand now how the ac relay works and how to get power to it. I still can't get over 70 degree air into the center vent. I have added gas up to the 45 psi mark on the low pressure side but fear not to go any further based on red lines on the meter and advice to not exceed the 50 psi mark as I could damage things. I replaced the expansion valve before evacuating and charging. And I have the clutch running.

This is converted R12 to R134a system. If that helps.

I saw your article about releasing freon and air on the high side. Should I consider something like that?

Don't know what to do next? Let winter come???? :)
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Briano1234
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Re: A/C troubleshooting

Post by Briano1234 »

GreenCabbie wrote:So I understand now how the ac relay works and how to get power to it. I still can't get over 70 degree air into the center vent. I have added gas up to the 45 psi mark on the low pressure side but fear not to go any further based on red lines on the meter and advice to not exceed the 50 psi mark as I could damage things. I replaced the expansion valve before evacuating and charging. And I have the clutch running.

This is converted R12 to R134a system. If that helps.

I saw your article about releasing freon and air on the high side. Should I consider something like that?

Don't know what to do next? Let winter come???? :)
Ah weedhopper, your heater valve is the issue it is allowing water to circulate in the heater core as it is either not fully closing or the cable is not getting the thing to the detent on the stop.
If water is flowing then the a/c usually can't over come the differential.... so you have hot air.

If the side vents are cold, then it is the heater core heater valve allowing water to move in the core, water moving in the core is 212 or greater.. and that is the issue.

Bleeding Freon is if you don't vacuum it down...
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:
GreenCabbie
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Joined: Wed Jul 18, 2012 11:17 pm
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Re: A/C troubleshooting

Post by GreenCabbie »

Hi Briano,
I have resorted to having a friend of mine who is a master mechanic but try 's to stay away for A/C systems help with this problem. Even though he try's to stay away from A/C systems he still works on them and has all the equipment. He just gets frustrated with all the models of vehicles he works on.
My Cabby's A/C is still not cooling. The Low Pressure and High Pressure sides of the compressor are almost exactly the same 100 to 105. We have tried adding R 134 converted to R 134 from R 12 just recently. The clutch on the compressor works. It's a new compressor.
We are baffled! We tried adding more Freon but the system wouldn't take on more. We replaced the expansion valve as well.
Of the components in the system-Condenser, Compressor, Low pressure valve, High pressure valve, Dryer, expansion valve, evaporator , and the control wiring and relay. All seem to be in working order. The system doesn't leak when we drew it down before putting in Freon.

Could my compressor be bad? Could there be too much Freon in the system?

I appreciate your time and any ideas you might have.

Thanks,
Ben
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Briano1234
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Re: A/C troubleshooting

Post by Briano1234 »

Compressor stall is a possibility. (that can be a bad compressor or over gassing).
I have seen it, and have eventually replaced compressors for it.

Your pressures if static that is the compressor isn't running then that may be normal as it really has equal pressures at rest.
Your pressures if running aren't normal.
should be
low side 15 to 30
high side 150-210

So I would bleed off some of the gas, as I remember that you said you had 40oz in it and that is about 8 oz too much.
Refridgerant
85-91 2.5 r-12
92-93 2.06 r-134a

When you bleed off the gas remember that you have to let the system stabilize for about 3-5 minutes, prior to restarting the compressor.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:
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