Heater/a.c Problem

[SGILWHITE]

hi guys

ive posted about this before and still cant find out what the solution is. dont want it to be an electrical gremlin that cannot be sorted.

so....if i turn on the air con and/or put the heater temperature FULLY onto maximum heat i hear a click, the engine revs drops, i hear another click then the revs return. this cycle continues until either the air con is turned off or i move the heat off of maxmimum. i can move the heat one notch above the maximum and the problem stops.

i have checked for leaks, changed a few cheap things like tps, idle valve, done an ecu reset.

it has got to be something that is triggered when either the ac is turned on or the heater is put onto max heat temperature on the heater. im guessing one of the fans comes on automatically and the clicking im hearing is the ac condenser clicking on and off. the clicking as i said about also happens when the heater is fully on heat and the ac is off. v odd.

it will do either when the engine is hot or cold. if its cold it will start clicking etc after about 10 secs but when the engine is at temp it will start doing it instantly.

anyone give me some guidance please? what else can be checked?

steve

[artscot79]

Sounds like either the aircon needs regassrd or theres a fault or leak in the aircon system that click I the aircon compressor cutting on and off which on some models it shouldnt it sounds like an electrical issue best bet is have it checked as theres so many parts that can cause the issue from faulty switch a faulty high ir low pressure valve faulty engine fan faulty compressor

[SGILWHITE]

its already been re-charged and checked out.

when the heater is turned fully onto max heat the same cycle happens....why? the air con is off so why does the same cycle happen? what does the heat and air con have in common? the only thing i can think of is that they both switch on one of the fans. the heat wont try and turn the compressor on will it?

[iantt]

If you have the direction to windscreen on hot it will put aircon on to demist screen

[SGILWHITE]

the direction can be on anything as long as the temp is on heat it will cause the issue.

you say when the direction is on the windscreen and on full heat the air con will come on to demist the screen but the light on the air con button doesnt come on. you can hear the compressor clicking on and off though.

as you can her the compressor clicking on and off no matter which its on it must be something to do with that.

what switch(s) could be faulty apart from a faulty compressor?

[artscot79]

Nothing that a diy mechanic can test you say its been checked out but it will need an aircon diagnostic specialist to check it with all the proper equipment.. the fact the light isn't coming on when windscreen is selected is telling you there's a fault you've got high n low pressure valves electrics etc as I say nothing a home mechanic can deal with since its a heat issue it could be anything even a leak

[SGILWHITE]

i had kwik fit run a diagnostic check a couple of weeks after the air con was re charged.....no faults. no error codes either.

[artscot79]

Yeah kwik fit a proper aircon diagnostics wont be found that way they connect hoses and meters up to the high and low valves and test it to ensure all valves are working and micro switches then they switch aircon on and again look at meter readings you need a mobile aircon specialist not a Kwik fit muppett you wont find an aircon fault by plugging a code reader in they know that but charged for it anyway

[SGILWHITE]

ok ill look into a specialist.

i have my own fault code reader, kwik fit didnt use one.

thanks mate.

[Micro]

Disconnect the AC clutch, try again. If it stops then it is related to the AC system.

May be a faulty clutch/compressor or pressure switch (it thinks its empty when it's not)?

[SGILWHITE]

just been lookin at videos on youtube about the compressor clutch.....

how do i disconnect the clutch? is there a wire/harness going to the clutch?

how can i tell if its either the high or low pressure switch that might be causing the issue?

[artscot79]

Again you cant diagnose pressure switches you need an aircon specialist with the equipment to do this

[IINexusII]

does the fan actually come on?

you need to visually see if it turns on when the a/c is turned on. what you are seeing is the compressor clicking on, but automatically shutting off after a few seconds due to the increase in heat/pressure in the system with no fan to remove the heat

try turning the A/C on while driving down the motorway, does it work fine?