intermitent air con clutch

[forget]

In the last week or so the aircon compressor in my 1990 range rover seems to be playing up.the magnetic clutch continually engages and diengages making a clicking noise. It does it all the time.. It doesn't seem to effect the working of the aircon as it still cools OK.

Has anyone else had this happen or has anyone got any ideas why it is happening and how I can fix it.

I have done the following tests

i have gas in system

bypassed/shorted hp and lp

also bypassed condesor fans

and swapped over some relays(namely clutch relay)

i have also done some metering,and found that when i disconnect the compressor/clutch i have between 12.45-13v at the plug and also at the relay feed out to the clutch.

what i have noticted though after 10 beers last night and more than that tonight is

the inputs to the relay do not drop out (bypassed/shorted)guessing they are the hp/lp maybe

when i hook the clutch/compressor plug back up and check voltage from the plug output ,it drops to around 11.75-11.85v(remains at 12.45-13 at relay output).and when it cuts out ,well ofcourse nothing,is there some sort of resistor in the clutch to regulate the power causing this.

all help appreciated ,thanks again

shane

also i have run direct power from battery to the clutch and it doesnt drop out

[roverv8]

In the last week or so the aircon compressor in my 1990 range rover seems to be playing up.the magnetic clutch continually engages and diengages making a clicking noise. It does it all the time.. It doesn't seem to effect the working of the aircon as it still cools OK.

Has anyone else had this happen or has anyone got any ideas why it is happening and how I can fix it.

I have done the following tests

i have gas in system

bypassed/shorted hp and lp

also bypassed condesor fans

and swapped over some relays(namely clutch relay)

i have also done some metering,and found that when i disconnect the compressor/clutch i have between 12.45-13v at the plug and also at the relay feed out to the clutch.

what i have noticted though after 10 beers last night and more than that tonight is

the inputs to the relay do not drop out (bypassed/shorted)guessing they are the hp/lp maybe

when i hook the clutch/compressor plug back up and check voltage from the plug output ,it drops to around 11.75-11.85v(remains at 12.45-13 at relay output).and when it cuts out ,well ofcourse nothing,is there some sort of resistor in the clutch to regulate the power causing this.

all help appreciated ,thanks again

shane

also i have run direct power from battery to the clutch and it doesnt drop out

Well you just about covered it all, only thing you haven't mentioned is the thermostat switch that regulates the temp, cuts the compressor in and out depending on the temp.
On my 89 RRC it's in behind the the centre of the console where the hot/cold/fan/AC levers are. Fun to get to.
Mine failed completely and the auto elec couldn't work out why.
I took it home and put a jump wire on it to test and off it went, had a spare on a wreck, worked for a few weeks and now it's blown the seal on the compressor - Just great!!

What happens if you slide it from say from 100% cold to say 70% cold,
See if it changes any behaviour of the compressor

Luke

[PhilipA]

AFAIR someone has posted before that the clearance in the clutch increases with age and the solonoid does not have enough power to pull it in .


AFAIR the fix was to machine the clutch a bit.
Maybe the poster can repost.

Regard sPhilip A

[forget]

thanks philip,i was looking at the clutch and found no problem .

i ended up pulling the dash out and found that where the slider is for the hot and cold ,it goes to a cable which must operate the vents,but what i found was that also the thermometer switch also conncts to the slider,which unfortunatly had become dislodged and left the thermostat on the heat control,hence there was my problem.:D

bloody **** of a thing!:twisted: