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Discussion Starter · #1 ·
It's 90 and humid, and so even though I have a convertible I want to get the AC working. I am converting to R134A, and have done this so far:

- Had a shop drain the R12
- Test system, and it held a vacuum for 30 minutes
- Charged the system to test compressor, and it worked
- Bought R134A kit that had 80% R134A and 20% ester oil in each can (pre-mixed stuff)
- Installed the new fittings
- Tried to pour one can into the AC Low Side fitting, but since the compressor wasn't turning, the can wouldn't empty. Nothing seemed to go in.

I was told to try to jump the AC compressor to get it running, and I tried running a hot wire directly to the switch on the compressor. I pulled the clip out, and tried running the hot wire to each of the metal prongs , nothing happened.

I've read on here, and it looks like there is another place to 'bypass' the low pressure cut off.

Can someone tell me what to do, and where to do it? Treat me like I am 4 years old and don't leave out any details, because I don't know the AC system. Pictures would be great. Even my Mustang Manual section on the AC says "leave this to professionals".

#1 - I need to learn how to do as much of this as I can
#2 - I'll save the professionals for the stuff I really can't manage

Also, in case I'll get a lecture, I know that this is not a long term solution as the compressor wasn't made for R134A, but for $40 for the kit, and $10 to drain/test the system, I'd be thrilled if the AC just works until October.

I appreciate all of the assistance I've been given on this site - you are my "band of brothers".

PS - Dublin OH "Fox Body Reunion" at the Dublin Arthritis Show July 10 & 11th, http://www.arthritisautoshow.com/swas_mustang.php
 

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Are you sure the can didn't empty? The can is pressurized and should discharge into the A/C system with no problem. It may take more than one can to get the low pressure switch to close and allow the compressor to cycle. You can bypass the low pressure switch by unplugging it and putting a jumper wire to connect the wires going to it. Don't do it for very long as it will burn up your compressor if there isn't enough oil in the system.

On a side note, did the kit you bought come with a replacement dryer? The dessicant inside the factory dryer is not compatible with r134a. I converted my system a couple years ago. No problems using the factory compressor, condenser, and evaporator after flushing. Only replaced hoses and dryer and assembled with new o-rings.
 

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Discussion Starter · #3 ·
I got the above post, and a private message, both with about the same info. On the top of the compressor itself there is an electrical plug, which is what I unplugged and ran a jumper to (hot wire straight from the + side of the battery - it had juice). The compressor didn't kick on when I turned the car on and turned the car to Max Air. It did turn on when the shop pressurized my compressor during their tests.

From some other posts it seemed like there was another plug or cutoff somewhere else to "jump", and I don't know where to look. Is it something on the evaporator? Previous owners of my car had so many stereo wires jumbled into the wiring that much of my car looks like a science kit, and I am not sure what I can remove.

My kit did not have replacement dryer. Just fittings, hose/valvle, and three cans of pre-mixed R134A and ester oil. Am I heading for short-term cool and long-term costs?

If this does blow up down the road, I would consider the AC delete route....but there are some awfully hot and sticky days in Ohio...and I am not looking for an extra 10th at the strip.
 

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The plug on top of the compressor is the power source for the clutch assembly. One wire is a 12V+ and the other is a ground. The dryer is on the passenger side firewall. Its the metal cylinder with one of the A/C hoses going into the top of it. The low pressure switch is screwed on to the top of the dryer and will have a two wire plug on it. Unplug that connection jump the wires (not the switch itself) and the compressor should kick on.
 

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I just did mine, follow this:
1. Follow the Low pressure hose to the metal cylinder on the passenger side firewall, on top of this metal can is a connector, unplug it and put a paper clip or jumper wire across the terminals (make sure if you use a paper clip that it does not touch any other metal)
2. start the car
3. turn the knobs to Max A/C, the coldest setting, and Hi fan
4. (compressor should be on) start putting in the freon
5. the system is to hold 2lb 2oz (34 oz) each can is usually 12oz so 3 cans will be 2 oz over so after 2 cans remove the jumper and reconnect the connector and then put in the third can while the compressor is on, stop putting in freon when the low side reading is at 30lbs or until the "gauge" that comes with the kit says full.
 

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Discussion Starter · #6 ·
I just came back from a nice long drive with the AC on, and all worked well. $40 plus tax, and I've got AC. You Rock, Notch.

Thank You All!
 

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glad to hear you got it done and working im still working on mine i gotta replace the oriface tube
 
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