A/C woes

82rabbitdiesel · Post by **82rabbitdiesel** » Wed Dec 12, 2007 9:40 pm

82 rabbit diesel, a/c doesn't kick in. fan blower works great as well as the heater. when i have just the vent on and the heat off there is still heat coming from the center vents. where can i check to start isolating the problem? it still has r12 but got the kit for the change over to 134a but have no clue what adapter goes where and what to do for the change. also got a set of gauges. the instructions were as weak as a glass of sun tea. i know to fill at the low side while it's running but if the pressure is low will i have to jump the compressor? is the low side at the front of the rad support?
has anyone done this that can give me some advice? searched and came up w/ nothing. TIA

VWCaddy · Post by **VWCaddy** » Wed Dec 12, 2007 11:33 pm

Usually a low pressure cutoff switch in the system. Not familiar with the VW A/C system, but on my Toyota it is under the dash in one of the A/C pressure lines. I recall on my old '81 (w/ A/C) you need to have the blower on for the A/C to kick in (I think you probably know this), but I remember a few tims I had the vehicle at the VW dealer shop, they would always write "A/C inoperative" on my ticket. It worked fine with the lever in the right position and the blower on.

If converting to R134, probably wise to have an A/C shop drain and recycle your R12 and pump down the system for you. They would probably show you where to hook up the adapters and what not, especially if you go to a small owner-operated shop.

Ziptar · Post by **Ziptar** » Thu Dec 13, 2007 6:16 am

R134 can put quite a load on our older low HP engines and not cool as well as R12.
There are R12a alternatives available., RedTekand DuraCool or search "R12a" on ebay, there is a dealer or two of other brands.

I have yet to use them but, have read a bunch. I will be charging the A/C in the Jetta soon, I am using Duracool.

Threads
http://www.thesamba.com/vw/forum/viewtopic.php?t=244201
http://forums.tdiclub.com/showthread.php?p=1384830

There are those that claim 12a turns a car into a bomb on wheels, I am not buying that. Test have shown 134a combined with oil under pressure is just as flammable.

bottleworks · Post by **bottleworks** » Thu Dec 13, 2007 2:01 pm

82rabbitdiesel wrote:82 rabbit diesel, a/c doesn't kick in.

it still has r12 but got the kit for the change over to 134a but have no clue what adapter goes where and what to do for the change. also got a set of gauges.

What makes you think it's low on R12? Have you checked for power at the a/c clutch coil? What are your gauges reading? Assuming that you do end up retrofitting, how will you be recovering the remaining R12 refrigerant? Do you have a vacuum pump to pull a vacuum before charging the system with R134A? Do you know what your doing?

82rabbitdiesel · Post by **82rabbitdiesel** » Fri Dec 14, 2007 11:46 pm

bottleworks wrote:
1.What makes you think it's low on R12?

2.Have you checked for power at the a/c clutch coil?

3.What are your gauges reading?

4.Assuming that you do end up retrofitting, how will you be recovering the remaining R12 refrigerant?

5.Do you have a vacuum pump to pull a vacuum before charging the system with R134A?

6.Do you know what your doing?

1.don't know if it's low or not, got a set of gauges but they are for 134A so have to put on the kit to get a reading.

2.haven't checked power at clutch, that's why i'm asking what to look for and a place to start.

3.haven't got a reading yet, haven't put on the the fittings yet.

4.the R12 will be evacuated by the local ac shop up the road from me.

5.no vac pump, will get the shop to do that.

6.i know more now than i did when i first posted these questions by people who actually answered them instead of asking a whole lot more questions than what my original post was.

for the record i didn't know/hadn't done before:
reseal injection pump
change/replace front/rear bushings/struts/shocks
recover headliner
re skin door panels
fit Caddy tail lights in place of long tails
install bolt thru vent windows
replace ac vent
repair rust on rear hatch
install front seat belts
replace steering wheel
replace shift bushings
build console/cup holder
tint windows.................
but i have now and didn't know how to or didn't have enough knowledge to do before i got my Rabbit, but thanx for your interest

VWCaddy · Post by **VWCaddy** » Sat Dec 15, 2007 12:31 am

The A/C clutch will have some wiring attached to it. Follow that back to the first connector and check there. Typically, 1 or 2 wires, 12 volt on 1 wire and ground on the other (if 2). You could apply 12 volts to the clutch to see if it is working or you could probe the connector with a meter to check for power.

82rabbitdiesel · Post by **82rabbitdiesel** » Sat Dec 15, 2007 12:35 am

VWCaddy wrote:The A/C clutch will have some wiring attached to it. Follow that back to the first connector and check there. Typically, 1 or 2 wires, 12 volt on 1 wire and ground on the other (if 2). You could apply 12 volts to the clutch to see if it is working or you could probe the connector with a meter to check for power.

thanx VWCaddy, will look at it on next days off

bottleworks · Post by **bottleworks** » Sat Dec 15, 2007 4:48 am

6.i know more now than i did when i first posted these questions by people who actually answered them instead of asking a whole lot more questions than what my original post was.

That's cute. Because you did not provide enough information, I had to asked you questions. However, based off you attitude, you apparently know how to diagnose and repair your problem. Myself, a heavy diesel mechanic, ASE master tech, and refrigerant handling certified person will not provide you any assistance now or ever. Enjoy your life and I hope you know how to correctly charge your system.

crankpot · Post by **crankpot** » Sat Dec 15, 2007 3:42 pm

The '81 has an ambient air temp switch located behind the grill. If your 82 has one as well, it will inhibit A/C operation at low temperature like we get int he winter.

Bob

82rabbitdiesel · Post by **82rabbitdiesel** » Sat Dec 15, 2007 5:01 pm

crankpot wrote:The '81 has an ambient air temp switch located behind the grill. If your 82 has one as well, it will inhibit A/C operation at low temperature like we get int he winter.

Bob

thanx crankpot, i will take your advice and look at it.

backwoods · Post by **backwoods** » Sat Dec 15, 2007 9:21 pm

Hi -

I don't know if this will help any, but I have an '81 with what seems to be a dealer installed add-on A/C. Your R-134a kit should have ports that screw overtop of the old R-12 ones, red (high) over the one up near the radiator and blue (low) on the one down by the compressor.

Mine has no ambient air switch, and the entire A/C air handler is completely separate from the heater system, with its own blower down under the glovebox area; the A/C vents are on the sides and the two below the heater controls. The A/C blower runs on its own switch. It is good advice posted earlier to see if there is 12V being applied to the compressor clutch. Also, mine had a diode in the wiring harness to the fuse panel that was wired to turn on the radiator fan whenever the A/C clutch was on, but it was burned up and I had to replace it.

If you don't want to hassle with R-134a and change the oil (I did that anyway since mine was long ago empty), there is a substitute called Enviro-Safe that works with your old oil or the ester/polyol oils. I'm using it and it works like gangbusters, really cold. On a clean/vacuumed system, it took 24 oz to fill the system. The low side tended to stay a bit low, around 30, when the high side got up around 150. These numbers are from memory so maybe a bit off.

My thermostat worked fine and kicked on the compressor no problem, so I cannot help there.

tony

Post by **Fatmobile** » Sun Dec 16, 2007 12:21 am

The '81 has an ambient air temp switch located behind the grill. If your 82 has one as well, it will inhibit A/C operation at low temperature like we get int he winter.

Great info. I always wondered what that was.

82rabbitdiesel · Post by **82rabbitdiesel** » Sun Dec 16, 2007 10:36 pm

backwoods wrote:Hi -

I don't know if this will help any, but I have an '81 with what seems to be a dealer installed add-on A/C. Your R-134a kit should have ports that screw overtop of the old R-12 ones, red (high) over the one up near the radiator and blue (low) on the one down by the compressor.

Mine has no ambient air switch, and the entire A/C air handler is completely separate from the heater system, with its own blower down under the glovebox area; the A/C vents are on the sides and the two below the heater controls. The A/C blower runs on its own switch. It is good advice posted earlier to see if there is 12V being applied to the compressor clutch. Also, mine had a diode in the wiring harness to the fuse panel that was wired to turn on the radiator fan whenever the A/C clutch was on, but it was burned up and I had to replace it.

If you don't want to hassle with R-134a and change the oil (I did that anyway since mine was long ago empty), there is a substitute called Enviro-Safe that works with your old oil or the ester/polyol oils. I'm using it and it works like gangbusters, really cold. On a clean/vacuumed system, it took 24 oz to fill the system. The low side tended to stay a bit low, around 30, when the high side got up around 150. These numbers are from memory so maybe a bit off.

My thermostat worked fine and kicked on the compressor no problem, so I cannot help there.

tony

thanx backwoods, more useful info. it's too cold for me(35)right now so will save all this info and use it when it warms up. by WED it will be back up to 75.

82rabbitdiesel · Post by **82rabbitdiesel** » Mon Dec 17, 2007 9:55 pm

i've been to Regina, your capital and also Moosejaw. nice place in the winter. have in laws in Coleville, SK

Former VWDieselParts.com Forum

A/C woes

A/C woes

Re: A/C woes

Re: A/C woes

A/C on my 81

Re: A/C on my 81