Jump to content

BMW 5 Series Owners Board uses cookies. Read the Privacy Policy for more info. To remove this message, please click the button to the right:    I accept the use of cookies

Photo
- - - - -

AC stopped - Could Final Stage Resistor be cause?


  • Please log in to reply
7 replies to this topic

#1 DennisCooper

DennisCooper
  • LocationSlough West London/Heathrow
  • Current Car:Ex Police - E39 530d Touring

Posted 29 July 2010 - 04:34 PM

Hi all

6-8 weeks ago, I switched my AC on and I got some cold air and then petered out. I then switched the AC off and had the temperature on the lowest setting and I still got warm/hot air. Classic Final Stage Resistor failure symptoms.

today I had my AC re-charged and switched the AC on and got no cold air. Looking at the engine its clear that the AC compressor is not spinning - could it be possible that as the Final Stage Resistor is kaput, that it knocks out the AC compressor switch on as well?!

I'm hoping by changing the FSR the new part will 'send the signal' to switch the AC compressor on. The machine today said that theres no leaks in the system as it tests the pressure prior to taking the old gas out before refilling.

Anything else I can try or get my mechanic to look at that's common to fail or not work with the AC system?

Cheers, Dennis!

IMGP4911-1.jpg

 

Tel: 07708 804500 10am-9pm 


#2 bigjay

bigjay
  • Locationsunny southport!
  • Occupation:refrigeration/airconditioning engineer also sitting in my hottub drinking beer
  • Current Car:E39 535i, Porsche cayenne turbo!

Posted 29 July 2010 - 04:37 PM

The fsr is for the fan inside the cabin and not the a/c comp! When you switch the a/c on is there a load pit on the engine? If so it sounds like you've got a seized comp!!

#3 Estoril-5

Estoril-5

    Principal Member

  • Platinum Members
    • Member ID: 28,666
  • 3,441 posts
  • LocationBirmingham, West Mids

Posted 29 July 2010 - 05:06 PM

could it be the heater solenoid thingy?
E39 Sport

I like both..but the 42's just give it that edge 8)


#4 mickk44

mickk44
  • LocationSurrey
  • Occupation:Electrician
  • Current Car:E39 535i se with tasty bits.

Posted 29 July 2010 - 05:18 PM

Is the compressor not controlled by a solenoid clutch that either lets the comp pulley either idle or drive the compressor?
I had an old rover and this happened to me, it was a rather large three pin electronic power switching relay that was not switching the electric clutch.
Posted ImagePosted ImagePosted ImagePosted Image

#5 ciggy535i

ciggy535i
  • LocationGloucester, UK

Posted 29 July 2010 - 07:54 PM

Well, it could be one of many things. Any number of sensors, valves, fans etc. It maight be worth getting the A/C fault codes read.

A common fault is the condenser fan (in front of the radiators) can seize- check it spins freely.

You can apply 12V directly to the compressor briefly. See if the clutch clicks in to rule out this.
1996 E39 535i, V8 and a manual......

#6 Trisman

Trisman
  • LocationCowfold, Nr.Horsham, W.Sussex.
  • Occupation:Project Management, Construction industry.
  • Current Car:E39 532i Touring. 'E12 M535i. 635CSi manual. Smurf 540i Now manual!

Posted 29 July 2010 - 08:23 PM

Dunno if this'll help, but I had a failed FSR on a '97 Touring recently.

The blower fans were completely dead, but the compressor was still kicking-in and cold air would dribble out of the vents.

One new FSR (well, second hand!) & it's all working.

So, I reckon the FSR doesn't effect whether or not the compressor clutch will engage or not.
Trisman.

Current: E39 Touring B10 3.2 Alpinalike in Oxford Green.
Alpina 3.2 engine & gearbox mit flappy paddles. 19" Alpina alloys, spoiler & interior.
M5 Brakes, roof-rail delete.
E12 M535i Kashmir Gold, 16" open-lug Alpina alloys.
E24 635CSi manual. Style 5 Alloys, lowered B5 suspension.


Gone: E39 '00 530i Sport manual Red.
'98 528i SE Auto Arctic Silver. (237k miles!)
E28 M5 No.8, (now in Germany, in bits?).
E28 M535i NO2 Monster, Red.
E24 635CSi, Blue,
E28 M5, Lach silver.

#7 ally

ally
  • LocationAberdeen
  • Current Car:E39 530i Sport Aegean Blue Edition

Posted 29 July 2010 - 10:59 PM

FSR is nothing at all to do with the AC, if your compressor is not turning, then check the operation of the magnetic clutch, check the fuse & check the system pressure, if you had a bad leak for example, the system would not run as the LP switch would hold it off

2003 E39 530i Sport Aegean Blue Edition

2006 Ford Focus C-Max 1.8 TDCI


#8 DennisCooper

DennisCooper
  • LocationSlough West London/Heathrow
  • Current Car:Ex Police - E39 530d Touring

Posted 29 July 2010 - 11:46 PM

Cheers all!

I'll be soon giving my car to my mechanic who'll be able to sort this out for me and a few other little niggly things as well :)

glad the machine did that test today, not sure how reliable it is, but I don't have leaks apparently! hope the fix isn't too pricey !

Thanks, Dennis!

IMGP4911-1.jpg

 

Tel: 07708 804500 10am-9pm 





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users