GT3 Air Conditioning Fault

[GordonMasson]

When I bought the GT3 the air con wasn

[fjmuurling]

There is a pressure switch on the receiver/drier. When the pressure is too low it cuts out and than the electromagnetic clutch on the compressor can not engage hence no AC. This switch is a safety device in order to avoid damage to the system when the pressure inside the system is not correct. I suggest to have the system pressure tested to see if there are no leakages. If the pressure is right it can be a broken (pressure)switch. Have you checked the V-belt which drives the compressor ?

Freek

Edited April 30, 2008 by fjmuurling

[GordonMasson]

The Air Con was re-charged when the Cam belt was replaced a couple of weeks ago so all the belts were off the car at that point and then replaced again.

Do yo uknow what the switch is supposed to read under normal opperating conditions... ie is it a short circuit or an open circuit?

To verify if this is the fault, will it be ok to mimic the correct setting for the switch for a couple of seconds to see if the cluch does come in?

[lotus4s]

Gordon,

Personally speaking I would recommend taking it to an a/c specialist and letting them diagnose it if you don't have the proper tools and know how to do it yourself. It's a typical a/c system and any good mechanic should be able to diagnose it in short order. At least you won't be replacing parts you don't need to.

There are several things that can cause your problem and the pressure switch is only one of them.

Cheers,

[fjmuurling]

When the pressure is ok the switch closes so under normal operating conditions it "shorts".

Freek

[Paul93Lotus]

The hi/lo pressure switch is attached at the receiver/drier under the front bonnet....near the headlight. You could temporarily jumper the switch to see if the compressor clutch locks...at least that would rule out a faulty compressor clutch.

A clog within the line "what is referred to sometimes as black death" could cause the pressure to skyrocket and kick in the switch. If this is what is wrong, leaving the switch jumpered for long could lead to a hose bursting. Having an a/c manifold gauge set hooked up would answer a lot of questions regarding standing pressure and pressure while the system is working.

There is also another switch located under the dash that can go bad, but that is a lot harder to get at, so hopefully it is not that. The main switch at the a/c controls could also be bad (no signal to compressor).

Good Luck!

Edited April 30, 2008 by Paul93Lotus

[gghc87]

Gordon

Had a similar problem see here

http://www.lotusespritforum.com/forums/ind...showtopic=11137

[GordonMasson]

So now im getting somewhere

[gghc87]

Yes, but on the G Car

see here

http://www.lotusespritworld.com/EGuides/EM...C_Charging.html

[fjmuurling]

Gordon,

It can be a faulty switch but my bet is on a low system pressure. According my electrical manual the switch is labelled as a low pressure switch but normally the switches are high/low pressure switches. In order to replace the switch the system has to be emptied. Have the pressure tested / charge checked at a shop which is specialised in AC systems so you know what is wrong.

As far as the switch concerned the settings depend on the type of refrigant being used, so any switch which fits and is for the correct type of refrigant can be used IMHO.

Freek