Air Con Compressor

[Busman]

Almost managed to get my air con working. The system has had a new compressor and some pipe work and now holds its pressure.

The last problem is the power to the air con clutch. I've got 14.3 volts to the conector at the compressor, but it wont cut in. If I put a supply straight to the compressor, then it cuts in and loads of cold air is produced.
What stumps me is why is there power getting to the compressor but it wont cut in, but it will cut in if you give it a supply straight from the battery?
I've got as far as checking the bsi, and you can hear the solinoid cutting in as you press the ac button with the engine running?

Any thoughts?
Richard

[Doggy]

It's possibly a duff relay in the BSI - if the contacts are in a bad way, they can conduct enough to give you a voltage reading, but refuse to pass enough current to work the clutch. I suggest rigging up a test load - an indicator or similar 21W lamp would be good - see if the clutch wiring will light that up.

If it's OK. make sure the earth lead in the clutch connector is OK.

Let us know how you get on

[Busman]

Hi Doggy, and thanks for your thoughts.
The relay in the bsi is almost certainly the cause. Do you know if its replaceable? Could one get inside it with a points file and clean the contact? Would it be possible to add another relay outside the bsi powered from the little bit of power that this one is still producing?
What i've done as a temporary fix is to run a power supply direct to the compressor from the cigarrette lighter socket as a test. When i plug this in driving down the road, I get huge amounts of cold air. This would seem to indicate that the basic system is ok, its just the bsi as you suggest.

I'll try the bulb test on my next day off.

Many thanks,
Richard.

[Doggy]

Richard,

Have a look at this: viewtopic.php?f=1&t=14849&hilit=+bsi+%26+relay
(you'll probably need to sign to the coupe club).

Be careful with the direct feed - the ecu can't turn the compressor off if it needs to on low or high pressure.......

[puggy]

When i had this prob it was the curly wire resistor things on the front of
the rad also the pressure switch/sensor on the side of the condensor will cause this problem if knackered !!

[Busman]

Richard,

Have a look at this: viewtopic.php?f=1&t=14849&hilit=+bsi+%26+relay
(you'll probably need to sign to the coupe club).

Be careful with the direct feed - the ecu can't turn the compressor off if it needs to on low or high pressure.......

Hi Doggy.

Many thanks for your valuable thoughts on this. The continuious live feed is mearly a method for me to test that the system works. As you suspected, the main problem is this relay in the bsi. Which clearly needs to be changed. Now all i need is to find someone a bit handier with a soldering iron than i am.

Hi Puggy.

I know exactly the two thermal resistors that you are refering to, because i changed them last year. As you say, they did cause symptoms very similar to this.

Many thanks for all your help guys.

Richard.