air con fuse blowing

[GBH14]

after getting my SERV light come on last night, I plugged my car into my RSTuner and it had numerous 'air conditioning exit' faults. so I checked the fuse and it had blown.

So i changed the fuse for the same type that was in there and I tested quickly and the SERV light went off and my fans were working.

Then this morning when pulling off the drive, with the air con on, the fuse blew again.

Can anyone give me any pointers as to what may be causing it to blow? and also confirm the type of fuse that should be in there?

Thanks

 

[GBH14]

Update

I have tried putting another fuse in and turning the air con off, leaving just the blowers on - all is fine. but as soon as i press the AC button it blows the fuse again and i have nothing.

am I right in thinking the cooling fan is linked with the AC? if so then i have eliminated the fan being the cause, as i took it for a drive, then fan kicked in and the fuse didnt blow.

so im thinking air con pump?? can anyone confirm this?

 

[MicKPM]

The cooling fan is a two stage unit so when the AC is on the demand request is sent for "Stage 1" and the fan blows at a slow speed to keep air flowing thru the heat exchanger. The cooling fan is "Stage 2" and is a much higher speed. If you don't mind blowing some fuses you can always unplug the AC Fan control and see if it 'pops' the blade fuse to rule it out.

The problem could be in a few places; I'd start with the AC compressor as you suspect above and the wiring to it fixing any signs of obvious damage. Again, unlpug it and try again to rule out a component break down Vs a short to pos/gnd. Another place to look is the AC relay in the under-bonet fuse box (IIRC it's the 30A Yellow unit). What ever you do, do NOT be tempted tp put a larger rated fuse in to the circuit as the AC has a fairly hefty pull to it and you will be risking a fire if it doesn't 'pop' the blade fuse.

Mick

 

[bmh.01]

Last one I saw like this the a/c clutch control wire was shorting to the block. It'd run hit and miss surprisingly, but always popped in the end.

 

[GBH14]

The cooling fan is a two stage unit so when the AC is on the demand request is sent for "Stage 1" and the fan blows at a slow speed to keep air flowing thru the heat exchanger. The cooling fan is "Stage 2" and is a much higher speed. If you don't mind blowing some fuses you can always unplug the AC Fan control and see if it 'pops' the blade fuse to rule it out.

The problem could be in a few places; I'd start with the AC compressor as you suspect above and the wiring to it fixing any signs of obvious damage. Again, unlpug it and try again to rule out a component break down Vs a short to pos/gnd. Another place to look is the AC relay in the under-bonet fuse box (IIRC it's the 30A Yellow unit). What ever you do, do NOT be tempted tp put a larger rated fuse in to the circuit as the AC has a fairly hefty pull to it and you will be risking a fire if it doesn't 'pop' the blade fuse.

Mick

Nice one mate, thanks for the pointers, I will have a check of these and hopefully find the cause...

 

[GBH14]

bringing up my dead thread but i need some more help..

after carrying on changing fuses to try to find the fault, it eventually stopped happening and they worked fine. Then a month or so later i had the fans on full blast, there was a click and they stopped blowing, only this time the display was still illuminated allowing me to change the temp etc but the fans wouldnt blow. I then had the rheostat replaced and hey presto, its worked again. I had no probelms from then until the other day.

I was driving with my fans on (not a/c though) and suddenly the fans went off, the heater display went off, serv light came on, and auto wipers stopped. this is exactly what i had at the start of this thread except it was only happenening when i used the A/C the first time, now its happening on normal fans.

I keep replacing the fuses and trying to find out what it is but I am stumped. Has anyone got any ideas? really bugging me now.

 

[MicKPM]

Did you do any of the above? It deffo sounds like something is drawing more current than it should be due to a fault or short.

Mick

 

[GBH14]

Did you do any of the above? It deffo sounds like something is drawing more current than it should be due to a fault or short.

Mick

Im pretty sure its not the AC fan, and its definitly not AC relay in the under-bonet fuse box. In fact im pretty sure its not even related to the AC at all, as it is blowing the fuse without turning the AC on, or is it all going to still be linked? surely with no AC on then the Pump, fan etc are out the equation?

I noticed last night when driving that my rear wiper, rear screen wash and front screen wash dont work either, and also my reversing lights. Surely about 10 different components arnt on the same fuse?! sounds ridiculous if they are, but they have all gone at once which leads me to think they are. Can any confirm if this is the case?

EDIT - Seems that it is...

F3 Fan in a box 15A Windscreen wiper compound control, Reversing lights switch, Air conditioning control panel, Passenger compartment temperature sensor fan, Air conditioning control unit, Footwell vents air conditioning distribution motor, Rain sensor computer, Starter relay, Discharge bulb ECU, Headlight adjuster motors,

Would be the fuse that has the most amount of investigating to do..

 

[GBH14]

Can someone also confim something else for me...

It says in my last post that it should be a 15A fuse. Now, are all 10A fuses red? I know i have a blue fuse in there but I'm pretty sure it was a 10A fuse, but cant 100% remember and cant go to my car at the minute

 

[Amos91]

Did you do any of the above? It deffo sounds like something is drawing more current than it should be due to a fault or short.

Mick

Holy thread bump, mine has started blowing the 15A fuse as soon as the air conditioning is turned on(currently unplugged the pressure sensor so I don't accidentally do it again when demisting...)

Is it typically a wiring fault or the compressor on its way out?