Thread: air cond problem linked to fan

Hi,

replaced mine screws off pretty easy around $400 odd dollars for a new one. Best price was from a company in Sydney we cannot mention on here.

Cheers

Originally Posted by DRUT

Had my 99 defender in the other day to have the air cond looked at, gets very cold and lots of condensation around the ports. was told by the auto elec that the viscous fan can be stopped by hand which causes high pressure in the air cond compressor which is the cause of the problem, the air cond working at max all the time. whats involved in replacing the viscous fan and how much am i looking at ??? will this fix my air cond chill problem??

Can't agree with the auto elec on that.

If the viscous fan is not functioning properly then it generally happens that not all of the high pressure vapour is condensed into a high pressure liquid.

The high pressure liquid enters the tx valve and is 'throttled' then allowed to expand / evaporate off in the evaporator - however if not all of the gas has been condensed into a liquid, and thus remains a vapour it can not be throttled, and to a certain degree it will not expand as it should and in fact remains a vapour (superheated at that) so the effects of a bad condenser fan can cause the evaporator to turn into a warmer (Isay warmer as some gas is condensed, then evaporates, but the remaining vapour starts hot (no sub cooling) and stays hot and inturn warms the other gases in the evaporator.

The details you have given indicates to me that the gas charge in the system is incorrect.

I would still suggest you get the fan fixed, but in my opion it will not solve the problem.

You need the visc fan to cool the engine fluids.

After you have it done, get an air con tech to check the temperatures and pressures throughout the system, the superheat and subcooling settings. and the tx vale --incorrect refrigerant charge, a faulty TX valve or another restriction inn the system will cause the problems you state.

A visc fan coupling is about $400.00 - you need to grind down a standard open ended spanner to hold the drive tight while you undo the bolt

thanks ladas, I know you are the a/c guru so i thought you'd reply. I have noticed at low speed around town the a/c can sometimes not work as well or in fact blow slightly warm but at hisg speed its freezing. That is exactly what the auto elct told me to expect. he also services a/c by the way. I am getting the fan replaced even though the truck runs super cool and will go back and see him with your input, thanks heaps, cheers. let you know how I go.

Originally Posted by DRUT

thanks ladas, I know you are the a/c guru so i thought you'd reply. I have noticed at low speed around town the a/c can sometimes not work as well or in fact blow slightly warm but at hisg speed its freezing. That is exactly what the auto elct told me to expect. he also services a/c by the way. I am getting the fan replaced even though the truck runs super cool and will go back and see him with your input, thanks heaps, cheers. let you know how I go.

I have some interesting donumentation, unfortunately too big to post here, if you want it pm your email address and I will send it off

If it's running warm when you are around town, and cold at high speed - then yes the visc fan is the main culprit, but it should not overcool - there is more to this than just the fan.

The stat under the dash and the gas pressures should be looked at.

pm on the way

If its running cool , someone has taken out the thermostat because it was running hot, because the viscous fan is dead.
Are there no electric fans in Defender? Their functionis to force air through the condenser and to cut in as additional cooling..
The Viscous is mainly to cool the radiator on most cars including Rangie and Disco..
Regards Philip A

Originally Posted by PhilipA

If its running cool , someone has taken out the thermostat because it was running hot, because the viscous fan is dead.
Are there no electric fans in Defender? Their functionis to force air through the condenser and to cut in as additional cooling..
The Viscous is mainly to cool the radiator on most cars including Rangie and Disco..
Regards Philip A

X 2 !!!!!