Member No 1 posted:

mmm? what?
are you trying to change the laws of reverse cylce airconditioning des?

Des Lexic posted:

A common problem up here with the old window rattlers that freeze up in hot weather due to the heat exchanger freezing up and then going into heat to defrost the ice before cooling again. (On explanation provided by our local fridgy) BS??

Member No 1 posted:

des, in hot weather even a window rattler shouldnt freeze up...and i dont car how old it is....the temperature of the refrigerant should be well above freezing point. sounds like there is something wrong Des

In cold ..and i mean during winter cold...generally below 5c but may happen at around 8-10c the outdoor coil may begin to make frost and this could eventually cover all the outdoor coil reducing its ability (efficiency if you like) to pick up heat from the outside and deliver it to inside. When this happens, controls or sensors tells the aircon to do a de-ice...ie go onto cooling mode to defrost the outdoor coil so it can pick up heat...this cycle is usually only for a few minutes at most......

So des I think u have mis-interpreted what he said and have been wrongly applying it to the cooling cylce rather than the heating cycle

Des Lexic posted:

You are truely Member No 1 Thanks for the enlightenment. o:)

Member No 1 posted:

see i can teach an old dog new tricks hahaha

Des Lexic posted:

Who are you calling old.
I'm just a whipper-snapper

Member - Stephen M (NSW) posted:

Hi there Tim sounds like your evep cood be freezing up which wont allow the cool air to flow through so when you turn off it defrost itself and you start the procedure again. Need to get a thermometor and stick in air vents when air is on while you are travelling aroung and see what temp it gets down to. if it starts getting in the - degres you need to turn up the thermostat just a mill or to then repeat the procudure. This mainly happens with air cons that arnt factory fitted and have a manual thermostat screwed to the evap box behind the glove box. Another way to check is pop the bonnet up when this happens and see if your compressor is still cut in. I had the same problem with my hilux due to it being after market air. They dont normally do it around town because you are starting and stopping all the time and they dont have time to freeze up but on a long run they do. Air con should work between the temps of 1 to 4 degrees coming out your air vents. And yes I fitted air con to toyota's for 4 years so I do have experiance with them. Regards Steve M

Member - Stephen M (NSW) posted:

sounds like your evep could be ( spelling error)

Tim HJ61 (WA) posted:

Steve,

Thanks for the suggestions. It's actually a factory fitted unit, but your reply and this thread has given me some good tips to track down the problem.

Air does get very cold at the vent, but the multimeter I bought so I could play with things such as this decided not to work on Temperature setting, so until I get a replacement I'll just be sticking with the Exploroz scientific - geez the air cond's good.

Thanks
Tim

Member - Stephen M (NSW) posted:

No probs Tim yeah you cant go past the old nippondenso (toyota genuine) air con, best on the market I reckon, good things with toyota they normally have freezing cold air and a bloody great heater in the winter time. Take care Have a great weekend. Reards Steve M

Shane (QLD) posted:

Seems very strange to me, I have a 1983 60 series 2H Sahara with after market Turbo, the air con is converted to the new gas & it's never given me any trouble even on the hottest day.

HJ60-2H posted:

I agree that it is strange that anything would go wrong with a 60!!

micknjoan posted:

Thanks to all who replied. Beginning to eye circuit breaker with suspicion as the experts(?) appear to have canvassed the other options. Mick.