The Haynes manual remains tight-lipped about this procedure, doesn't even acknowledge that the arrangement in my petrol 1.8i with aircon, even exists!
It comprises two large fans mounted side by side in a moulded plastic mounting, having a triangular cover mounted top/central which contains the three relays.
From previous postings I know that the two fans have these characteristics:
1. They are interdependant
2. The voltage between them determines the rotation speed
3. The bitron controller sends the suitable voltage for engine temperature and aircon needs
4. The three relays juggle the voltage and either send to one fan (= 12 volts=high speed) or both in series (=half volts each=slow speed).
5. The system is designed to fail safe, and deliver high speed maximum airflow in the event of component failure.
Having removed, cleaned and electrolubed the contacts on the bitron sender without any result, I removed and replaced the relays one by one in a clockwise substitution experiment. This caused no difference to the faulty behaviour of my fan assembly, which continues to switch the only working fan (off side) into high and noisy revs when the engine is barely warmed up - this with aircon ON. It also does that every time the car is stationary at lights etc.
My reading of this behaviour is that the nearside fan has failed electrically or mechanically or lacks wiring continuity: consequently when an instruction for a sensible low speed (inaudible!) twin fan movement is sent, the 'fail safe' assumes a problem and sends off side fan into hyperdrive. And I mean hyperdrain on idling current available - the engine revs dip to half, the lights dim, anything electrical stutters or dies...accompanied by howling wind-tunnel noise: not good neighbourly behaviour in long traffic queues.
So how do I remove the entire fan assembly for inspection - Haynes isn't saying, and all wirings and motor mountings are concealed behind the large plastic moulding?
Any forum member who has done this job on a petrol aircon Xantia, who can offer the helpful advice-from-practical-experience for which this place is renowned, will be thanked in advance. Thanks!
Xantia cooling fans - removing for inspection
Moderator: RichardW
-
andycarter
- Posts: 170
- Joined: 01 Aug 2003, 03:49
- Location: United Kingdom
- My Cars:
- Contact:
I had to replace one of my fans last month. You don't have an intercooler so its easier (?)
Procedure is as follows:
1. Remove battery, airbox & battery tray and anything else in the way.
Remove indicators and grille if its pre 1998 (Haynes explains how), I think the charcoal canister on a petrol model will also need removing.
2. Disconnect radiator hoses (on mine I couldn't get at the bottom hose easily so left it attached - aircon compressor was in the way) Remove completely or just move radiator as far back as possible depending upon if you detached the hose.
3. Look down in front of the radiator and you'll see the a/c condenser, on the right hand side (from driver's perspective) you'll see the pipes going to the condensor. Don't be tempted to remove the central plate & screws unless you want to regas the system. The screws you need to undo are socket headed and hidden down inside a couterbore, one above and one below the two metal pipes. The lower one on mine was seized and it needed an assistant with a long reach 14mm socket throught the grille to stop the insert spinning - hope you have better luck [;)]
4. Loosen the a/c drier bottle from its cage and lift up because you need all the play available to move the condenser across so it's rubber lugs on the other end slide out of their sockets. Tilt the condenser back so you can get an arm down in front of it.
5. Remove the 3 nuts on the back of the fan motor.
6. Pull fan forwards - it will unplug itself.
7. Its a tight squeeze to get it out through the gap above the bumper in one piece but it will go with some persuasion, otherwise remove central screw (left hand thread!) and take it out in 2 bits.
Good luck!
Andy
Procedure is as follows:
1. Remove battery, airbox & battery tray and anything else in the way.
Remove indicators and grille if its pre 1998 (Haynes explains how), I think the charcoal canister on a petrol model will also need removing.
2. Disconnect radiator hoses (on mine I couldn't get at the bottom hose easily so left it attached - aircon compressor was in the way) Remove completely or just move radiator as far back as possible depending upon if you detached the hose.
3. Look down in front of the radiator and you'll see the a/c condenser, on the right hand side (from driver's perspective) you'll see the pipes going to the condensor. Don't be tempted to remove the central plate & screws unless you want to regas the system. The screws you need to undo are socket headed and hidden down inside a couterbore, one above and one below the two metal pipes. The lower one on mine was seized and it needed an assistant with a long reach 14mm socket throught the grille to stop the insert spinning - hope you have better luck [;)]
4. Loosen the a/c drier bottle from its cage and lift up because you need all the play available to move the condenser across so it's rubber lugs on the other end slide out of their sockets. Tilt the condenser back so you can get an arm down in front of it.
5. Remove the 3 nuts on the back of the fan motor.
6. Pull fan forwards - it will unplug itself.
7. Its a tight squeeze to get it out through the gap above the bumper in one piece but it will go with some persuasion, otherwise remove central screw (left hand thread!) and take it out in 2 bits.
Good luck!
Andy
Thanks Andy for that detailed procedure.
This far-from-easy job obviously needs to be looked at carefully before making a start, so I'll print off your instructions and see if I can locate all the items to which you refer...it's looking like a weekend job to me!
Incidentally, you state that you "had to replace one of my fans last month". Could you please say why? And how you diagnosed the fan to have failed rather than control/wiring/contacts. And did you have the same symptoms as mine? Surely you didn't buy a replacement (fan) until you were sure it wasn't some connector making a bad connection?
Any further info re: diagnostics will be thankfully received.
Thanks again.
This far-from-easy job obviously needs to be looked at carefully before making a start, so I'll print off your instructions and see if I can locate all the items to which you refer...it's looking like a weekend job to me!
Incidentally, you state that you "had to replace one of my fans last month". Could you please say why? And how you diagnosed the fan to have failed rather than control/wiring/contacts. And did you have the same symptoms as mine? Surely you didn't buy a replacement (fan) until you were sure it wasn't some connector making a bad connection?
Any further info re: diagnostics will be thankfully received.
Thanks again.
-
andycarter
- Posts: 170
- Joined: 01 Aug 2003, 03:49
- Location: United Kingdom
- My Cars:
- Contact:
I replaced the fan because it was noisy and vibrating. You could feel the play in the bearings was vastly greater than the other one.
It did still work though, so obviously different problem to yours.
Replacement fan was £5 from Looms scrapyard in Derby - took only 5 minutes to get it off a Xantia without a/c and no engine!
If you want to diagnose it without dismantling, go to a scrapyard and get the wiring loom out of the front, then you can trace which wires go from the relay block to the fan[8D]
It did still work though, so obviously different problem to yours.
Replacement fan was £5 from Looms scrapyard in Derby - took only 5 minutes to get it off a Xantia without a/c and no engine!
If you want to diagnose it without dismantling, go to a scrapyard and get the wiring loom out of the front, then you can trace which wires go from the relay block to the fan[8D]