Trying to get my AC working

[newsh]

When the RS2 intercooler went in the 3B AC pump wouldn't clear it. The clutch stuck too far out the front.
Thanks to an ABY Pump (smaller clutch mechanism), some pipes from Doug (thanks Doug) and a lot of messing about (3B and ABY systems have different thread sizes on the pipe unions ) we finally got my AC tested for leaks and (1/2) charged up today.
Trouble is the Pump wont run, clutch wont pull in, rest of the system seems to be ok, re-circ flaps and fan working etc.
Now I've been checking through my old thread about the relay positions (interior light problems) so I'll be double checking that tomorrow.
What would greatly help would be a circuit diagram so I can see what the relay is supposed to do and how the sensors relate, I'm thinking I've either got a duff relay or duff sensor or something plugged up wrong, the AC has never worked in the 2 yrs since I got the car.

So, Anyone got a circuit diag? Its a 92 3B simple system, not full climate control.

Are there any diagnostics for these, or any way of pulling codes?

TIA

[newsh]

There are sensors on the pipe in front of the rad. I presume one of these is a pressure sensor which stops the pump from rumnning if there is no gas in the system, anyone know which one it is?

[shadquattro]

There are sensors on the pipe in front of the rad. I presume one of these is a pressure sensor which stops the pump from rumnning if there is no gas in the system, anyone know which one it is?

If the system is short of gas( ie half charged -please explain why only half charged ) the lower pressure switch may detect it has little or no gas and will not allow current to pass to clutch ,on the clutch could try connecting positive power direct to the battery if the clutch is not at fault it will engage and if engine is running it should drive the compressor would suggest trying it with engine off first
the lower pressure switch is the green one both will need to be within perameter s to get the sytem giong although in this instance it unlike ly to be highside
could also try joining wires together that go to lp switch

[Sidspud]

Is your external temp sensor working OK? Aircon won't come on if the external temp is below 5°C.

[dkw_dude]

Codes:

http://www.20v.org/problem.htm select climate control

Low press. is behind in the same area as the ECU, on mine the connector was loose. Pic taken from passengers footwell.

[newsh]

All good stuff and will be checking more tomorrow, relays it seems were in wrong posns but still no joy. Will check LP switch.

DKW this is not Clima, just basic AC, 2 switches next to the heater controls, I've used that page before though on my 100 avant, really cool..

AC man put in 1/2 charge cos if system was to come apart there would be less wasted gas, he said it was enough to run though..

[newsh]

Nobody got circuit diags?? Paul??

[newsh]

clutch pulls in with direct feed!

[Stick Insect]

All good stuff and will be checking more tomorrow, relays it seems were in wrong posns but still no joy. Will check LP switch.

DKW this is not Clima, just basic AC, 2 switches next to the heater controls, I've used that page before though on my 100 avant, really cool..

AC man put in 1/2 charge cos if system was to come apart there would be less wasted gas, he said it was enough to run though..

You don't waste gas John, by law the A/C bloke must purge the system and recover the gas. You should not lose any because it is recovered. Mine will be going in sometime, the system will be emptied by vacuum pump and refilled. That way the correct weight of charge will be put in.

Ask Tom ( Audiman) he knows about A/C.

David

[dkw_dude]

Its a 92 3B simple system, not full climate control.

Hmm must read the whole post next time..

[newsh]

You don't waste gas John, by law the A/C bloke must purge the system and recover the gas. You should not lose any because it is recovered. Mine will be going in sometime, the system will be emptied by vacuum pump and refilled. That way the correct weight of charge will be put in.

Ask Tom ( Audiman) he knows about A/C.

David

Strange, I'll have to ask again what the reasoning behind this was..

Wasn't able to do anything today and now I'm about to go on holiday, I think I'll be going without it working, oh well, was quite looking forward to having AC in the car...

[shadquattro]

have you checked the power to the lp switch on the condenser ,btw the fine for letting gas go is max £20000 and up to 5 yrs

[newsh]

There was no power on pin 30 (blk/grey or blk/blue wire?) of the Electroclutch Relay

Found the pressure switch on the pipe behind the glove box (same colour wires..), pulled off the terminals and shorted them together and Bingo!

Clutch pulls in and cool ish air coming through!

Just needs the full charge now, apparently AC guy was unwilling to put in the whole charge till he'd seen the pump running? I was not there at the time.

[newsh]

Oh yeah, thanks to all esp DKW Dude for the pic of where the lp switch is, how would you ever find that if you didn't know it was there??

[newsh]

Are there any possible dangers or issues with bypassing the LP switch behind the glovebox?