A/C Not Working....

[RAD2LTR]

Thread revival again... So, briefly I had the a/c system working last year until the low pressure hose rubbed through on the frame rail. I just got another hose and installed it. Pulled a vacuum for an hour, let it sit another hour and it didn't lose any vacuum. Set up the gauges, added refrigerant and now I can't get the compressor to kick on. There is 60 psi on the low side and 35 on the high side. I think this will normalize if I can get the compressor to run, but it has no interest. No click when I push the a/c button. I can't find any wires that are disconnected. What am I missing?

Thanks,
Will

[Dave @nz]

The normal thing is broken wire which leads from the l/h headlight area to the compressor, some times more than on brake in the same wire.
Disconnect the compressor wire and connect to 12v source you should hear the compressor click in, if not broken wire.

[RAD2LTR]

Which is the compressor wire? I see a couple that are hard wired, but nothing that comes off a clip that can be undone. The wires all look good, but hard to say. The blue a/c light does illuminate, the aux fan does not kick on when I push the button however. It does work when the engine gets hot, but not when the a/c button is pushed. The compressor does turn, I was able to turn it by hand with the engine off so I know its not locked up.
I also have the late dryer with one pressure switch on it. I installed everything correctly and was adding an oil and dye charge to the system when the hose blew.

I do think its something stupid like a broken wire somewhere. To be honest, I can't see any wires other than the ground going to the compressor. Where should they be plugging in (I'm looking for a pic of the compressor plugged in.)

Thanks,
Will

[RAD2LTR]

I think I found my problem. The positive wire is MIA, but I don't know where it should be going. All I can see is a plastic box type thing on the top/side under the low pressure hose. There is a wire the comes out of that and goes into the front of the compressor, but I can't see anything for it to plug into, or anything like that.

I have the behr 7062304492 compressor, BMW p/N 64521377947. It looks like its now NLA as well. I think my simple fix just got ugly.

Will

[Dave @nz]

Hi Will
The wire comes from the headlight area then down to the compressor temp switch then to the box on the compressor by the clutch, if the wire has broken off at the box or temp switch just dig enough of the glue and plastic out to expose the wire, solder on new wire and epoxy the connection.

I think that you have some other wiring issues as well and would not rush any repairs, with key on and engine not running when the A/C button is pressed the fan should go and A/C clutch click on that is as long as there is enough gas in the system to close the pressure switch on the receiver dryer.

http://www.realoem.com/bmw/enUS/show...diagId=64_1721
https://s14net.vbulletin.net/forum/s...ng-restoration
http://wedophones.com/Manuals/BMW/19...g%20Manual.pdf

Dave.

[RAD2LTR]

Like I said, last fall it worked fine. I did the new version drier conversion and everything worked fine. I didn't touch anything following the hose failure. I removed said hose, installed the new one. I don't know when the power wire going to the compressor broke and totally vanished. I'm shocked that both ends of the wire are totally gone. There is nothing down there to break the wire.

The aux fan will kick on if I jump the wires for the thermostat plug and push the a/c button. I have a feeling that it needs the compressor wire to be good to go in order for it to kick on otherwise. I guess I'll go out and see what wires I can find. Looks like it should be a black wire running down to the compressor.

Will

[RAD2LTR]

It looks like I'll need a waterproof connector, I found the plug where the compressor power wire plugs in, and sure enough the wire was broken. I tested to see if it was the right one by pushing the a/c button and got 12V at the terminal, it went off when I turned the switch off. The downside is, I can't seem to find just one of these special wires, only a pack of 10 for $70. (

06

REPAIR KIT WATERPROOF PLUG

X

61131382248)

That seems excessive since I'm going to have to put a waterproof spade connector in the other end so I can attach it to the compressor anyway. Does anyone have a used wire with a good male plug end that I can buy? I checked both Pelican parts and ECS and the only way I can get one of those is to buy the whole 10 pack of plugs with ends.

https://www.ecstuning.com/b-genuine-bmw-parts/waterproof-plug-repair-kit/61131382248/

Is there another solution that I haven't found?

Thanks,
Will

[Afish]

While we're on the subject.
what would be a suitable replacement compressor since mine is leaking from the shaft. And I would also like to do a 134 conversion.
what components have to be changed for that.
thanks,
Anthony

[RAD2LTR]

While we're on the subject.
what would be a suitable replacement compressor since mine is leaking from the shaft. And I would also like to do a 134 conversion.
what components have to be changed for that.
thanks,
Anthony

Not sure about the compressor, but R134 is bad news. Everything needs to be changed, from the evaporator, to the condenser, all the O rings, the soft flex lines ( I have a brand new R134 one that I bought and didn't use). Essentially to do it right, its a very big job. A better solution is Enviro-Safe. Its R12E, and is a better solution, works with all the stock R12 stuff and won't cause compressor black death. http://www.ebay.com/itm/Enviro-Safe-...RXQ0wb&vxp=mtr Its also very cheap.

Will

[Afish]

I'll look into it,
Thank You

[Brandon]

1. The compressor won't engage if there isn't enough pressure diferential in the system.

2. The R134a BMW conversion kit works as good as the R12

Incorrect - you should upgrade to the parallel flow condenser if you're doing the 134A conversion. 134 doesn't transfer heat as well through a traditional serpentine condenser. The parallel flow units are designed for 134A.

https://www.r3vlimited.com/board/showthread.php?t=218857

[Brandon]

Here is some additional info regarding my A/C refurb. I stuck with R12 as all of my R-12 components were new or able to be refurbished. I changed out the 22 tube condenser for a proper 44 tube unit as a PO apparently had the wrong condenser installed at some point. Comments are imbedded with each image.

https://flic.kr/s/aHskztBhtp

[RAD2LTR]

I did a quick check to see if the compressor would work by running a wire from the terminal down to the compressor where the old wire had broken off and got an audible click from the clutch engaging, so as soon as I can conjure up a replacement wire that I can use in the terminal, I think I can make things work.

Will

[Dave @nz]

I think the terminal you need is p/n 61130007452 and they are sold individually from BMW and are green wire attached to male terminal, the electric fan should go when the a/c switch is on.
My wire to the compressor I made a new harness for it and it is inside a 4mm heat proof black sleeve I brought from eBay.

http://www.ebay.com/itm/HIGH-TEMPERA...item33cf198353

[RAD2LTR]

I think the terminal you need is p/n 61130007452 and they are sold individually from BMW and are green wire attached to male terminal, the electric fan should go when the a/c switch is on.
My wire to the compressor I made a new harness for it and it is inside a 4mm heat proof black sleeve I brought from eBay.

http://www.ebay.com/itm/HIGH-TEMPERA...item33cf198353

I'll look into the p/n.

Its odd, if I unplug the temp switch in the thermostat that kicks the aux fan on when the temp gets warm, jump the contacts, when I push the a/c button the fan kicks on immediately. Plugged in correctly, it only kicks on if the thermostat tells it to. The compressor engages, fluid moves in the a/c system, but the fan doesn't kick on. Unplugged from the thermostat, jumpered, it kicks on with the compressor, but then I don't have it working for the cooling system. Clearly something is wonky, but I don't have the slightest clue where to start looking. For now I'd rather keep the cooling system working well over the a/c system cooling me at the expense of the engine cooking itself.

Its supposed to be 110 here the next couple days, we'll see how well my jury rigged setup works.

Will

[Dave @nz]

It is very time consuming tracing circuits, possibly a good place to start is to confirm that the cooling fan still has two operating fan speeds with the key on and A/C OFF.
Normal speed via the K1 relay.
High speed via the K6 relay.

The three terminal temp sensor in the thermostat housing is for turning on the low speed or high speed fan relays depending on water temperature, so you should be able to jump two terminals to get either fans working. Join terminals 1-3 = high speed fan and 1-2 = low speed fan. #1 terminal wire = green with black tracer. #2 =Black. #3= black with brown tracer.

High speed relay powers direct to the fan.
Low speed relay powers direct to the fan resistor then to the fan... the fan resistor has been known to fail.

Under normal operation A/C operates through the low speed fan until.

My best guess is the low speed fan resistor or low speed fan relay failure.
Dave.

[RAD2LTR]

Well, looks like my compressor has rolled over and died. With the compressor running, I was seeing zero pressure drop on the low side, and really no rise on the pressure side. The compressor was engaged, but it wasn't cooling, and the gauges both sat at about 80 psi on a day it was over 105 degrees outside. I kinda figured it was suspect, but this pretty much says that its dead.

It looks like Denso makes a new one, anyone have any feedback on it?

Will