AC Wiring short or low pressure switch problem? (Update)

[tripleMX-3chicMS]

i will start from the top. This issue is in the 93 SE AC system.
I was 30 minutes into an hours drive. The cold air from my AC
was slowly becoming warm. I purchased some of the 134 from auto zone.
The fitting didnt fit my unit. When i got back home i tried the R12 I have had for a while.
That fit but was already full. It only took a very tiny amount.
I checked to see if pump/compressor was working and yes it is.
So i jumped the switch and "MELTED a 14 gage wire & almost melted the plug".
I thought if it was going to draw that much power it would blow a fuse or something.

*Has anyone else had this problem before?

My guess was the clutch but with the wire melting.... i figure a short somewhere?

Do i have to buy a new compressor with clutch or can i just buy JUST the clutch if needed?
Cuz i looked and could only find the two together and not only a clutch alone.

Any ideas? (and yes i used the search before posting this) Thanks De

[Inodoro Pereyra]

The first thing you need to do is figure out why the fuse didn't blow. That's a real biggie, especially if you want to increase the odds of dying in a warm bed, instead of in a burning car.
Then, you need to find exactly WHERE is the short. The compressor clutch coil is a strong candidate, but it's not the only one. Make sure you find what's causing the problem, before you start buying stuff that will solve nothing.
If it's the clutch, you might find a replacement at an auto parts store. There's a few variables to consider: first, not for all cars you can find the clutch by itself. For some of them you can, but for others... and second, I don't know if the clutch for the R-134a compressor is the same one that goes on the R-12 unit.
If it is, you're in luck. If it isn't, this may be a good time to convert your system to R-134a.

[PoisonDrop]

So i jumped the switch and "MELTED a 14 gage wire & almost melted the plug".

Which switch did you jump? And which wires on the plug?

[tripleMX-3chicMS]

is there any way to test the coil to see if it is drawing to much power
or how much power it is drawing? How much is it SUPPOSED to be drawing?
Im also thinking the low pressure switch is melted/blown and that might be why
it hasnt blown the fuse.

[Inodoro Pereyra]

You need to tell us which switch you jumped, and which wires melted, as Poison asked you. Also, you need to figure out why the A/c fuse didn't blow, if the melted wires are the clutch wires.
Give us more data, and we may be able to help you.

[tripleMX-3chicMS]

i jumped the switch by the clear bubbler window. The wires that melted were
the ones i had in my hand that i jumped it with. The insulation from that 14 gage
wire (left over from building my shop) melted while i was jumping the switch.
I don't know why the fuse didnt blow. My guess is that the switch has also blown
cuz it has some melted looking damage on it.

I wanted to figure this one out, but
im affraid i will have to take it to Alabama or TN for trouble shooting and repair.
Very few people here are qulified to work on a car let alone the AC. No one here
thinks that Mazda made an MX-3 (mx3) (mx 3)......

[Inodoro Pereyra]

I've been doing some research, and for what I see, the switch is only connected to the compressor clutch.
Make sure the wire between the switch and the clutch is not shorted to ground. If the wire is good, the clutch is shorted.

[PoisonDrop]

Yeah I believe that's the pressure switch. It turns off the compressor when the refigerant is cool enough. Don't know how it works though. I'll look at mine tomorrow.

[tripleMX-3chicMS]

So.... the wire is still good. So that means the clutch is the problem?

I checked on buying a clutch and it looks like i have to buy the compresor AND clutch together.

I cant just get a clutch? Anyone know this for sure? Thanks for all the help, De

[Inodoro Pereyra]

I'd say it's probably gonna be very hard for you to get a clutch for an R-12 compressor alone. The compressor with clutch you can get from an auto parts store is gonna be an R-134a compressor. I'd recommend you to convert your system to R-134a. It's not gonna be much more expensive than buying the new compressor, and in the future you'll be able to refill your A/C at home.

[PoisonDrop]

I'd say it's probably gonna be very hard for you to get a clutch for an R-12 compressor alone. The compressor with clutch you can get from an auto parts store is gonna be an R-134a compressor. I'd recommend you to convert your system to R-134a. It's not gonna be much more expensive than buying the new compressor, and in the future you'll be able to refill your A/C at home.

+1

[tripleMX-3chicMS]

ok thanks guys for all the help. Im listing pics of the white GS
after paint in my worklog now. Take a look.

[Newfie_dan]

You can buy the clutch seperate but for what it costs its just as well to get 1 from a wrecker or opt for a ebay special since your in the US and not canada shipping should be reasonable. FYI you will need a special tool to remove the clutch, I got it from a loan a tool program at partsource. Ebay also has the tool for pretty cheap as well. Make sure you get a qualified A/C guy to drain the system first before you touch any lines to disconnect anything, a/c refigerant especially r12 is not to be messed with period. I swapped out the clutch on my buddies mx-3 and my escort gt back a few years ago since they were totally shot, took me about an hour to complete each time.

[PATDIESEL]

I would suggest you take it to a mechanic. AC is hard to diagnose. Yes the clutch is an easy culprit, but it could be the expansion valve or a blockage anywhere in the line. The best way is to start checking with with AC meters that will tell the mechanic the pressures of the lines. That will tell him where the problem lies and then he can start to really find the problem after narrowing it down to se section of the AC system. I would not throw 2-300 on a new compressor if it only needs a filter dryer and recharge or something similarly simple.

[Newfie_dan]

If you understand how an a/c system works its not hard to diagnose at all. I learned the system myself with online guides prior to learning it in school. Passed my test on it with a 98%, a/c is not hard you just need to understand the basics and how the system works and the proper precautions.