Elmas Xantia V6 and Musical Stuff

[CitroJim]

If one fan is O/C James - a common problem - then slow-speed will not work as each fan motor is in series...

It’s often sticky brushes and the guilty party can sometimes be persuaded to run by giving it a spin with a stick...

Xantia fans can be very frustrating

[white exec]

Slow speed - fans in series
High speed - fans in parallel
The 3 relays do this switching, and all 3 must be working (corroded blade contacts the most common problem), and so must both the fans, as Jim says, for slow speed to operate.
Be very careful with bridging and making guesswork connections - it's easy to produce a short circuit when working with these relays, as they are inter-connected, and frequently unfused, because of their very high load.

There are simply two +12v signal feeds to the relay threesome, from the engine ECU. One feed puts fans in series, the other into parallel.

If in doubt about the condition of the relays themselves, you can replace them (all 3 are identical) with a standard 30/40A automotive 'cube' relays (must have changeover contacts, i.e. SPCO), available anywhere.

You're on the right track with inducing low speed running by either pulling the coolant temp sensor, or switching on the AC. Sort this issue, and everything else should work. Sometimes a stout clout to an intermittent fan motor will induce a bit of movement, on a temporary basis, sometimes. You can also disconnect the fans, and connect a 12v lamp in place of each one. On Lo speed, the lamps should light at half brightness, on Hi speed both will be full brightness. This checks that the relays etc are doing their stuff.

[CitroJim]

corroded blade contacts the most common problem

It always happens... The set I got yesterday to rebuild Gabriel's fans are immaculate except one relay that's just beginning to show signs of corrosion on the lowermost pin....

It's always the same one too - the bottom one in the triangle... It must be where damp accumulates...

Always a good idea to pull them regularly and apply a bit of silicone grease to to them to keep any corrosion at bay...

James, if you do find one motor duff then it's vital it's replaced with an identical one else replace both with a matched pair else - due to the low-speed series-running - performance may not be 100% good...

Not all Xantia fans are the same either... V6 (and all 'big-engined' Xantias) have uprated fans compared to their smaller engined siblings...

[white exec]

Yes, identical fans essential. I think they were produced in at least four different wattages, from 180 to 310watt each. That latter (for V6 and 2.5 on the XM) involves some serious running current at 12v-14v!

[elma]

I was just planning refurbishing mine, brushes and bearings if needed. I think the only way to know whats going on is to check the fans themselves and their wiring.
I'm quite comfortable with that and they will work as expected once I've serviced them.


The bit I'm still struggling with is the 2 states of the fan
Ignition on = low speed
Engine on = low speed
ac on = high speed
Which, if the relays and fans were ok is what my fans would be doing.

Can't be the coolant sensor otherwise would go to high speed so I'm starting at the bitron and working outwards.

[elma]

Actually what I'm saying isn't right.
I need to check the relays again next week.
The combinations coming on aren't right at all.
Ignition on was left and changeover.
AC on was all 3.
Thats just weird, not what I described above.

[elma]

So how do the fans come out of a V6?

[CitroJim]

That latter (for V6 and 2.5 on the XM) involves some serious running current at 12v-14v!

And why relay bases are so easily cooked when there's a bit of corrosion present Chris! Xantia fans motors are supplied by their own individual 40A Maxi Fuse...

So how do the fans come out of a V6?

Grille off, fan blade assemblies off noting that unless clipped (rare on the high-wattage ones) the fan blade assembly centre fixing screw has an LHD thread...

Once the blade assemblies are off, you need a cut down 10mm socket that will squeeze in between the fan motor fixing studs (three per motor) and the aircon condenser. Space is tight.

I made up a tool to do it comprising a ground down 1/4" drive socket with flats ground on the side to take a 15mm spanner. That spanner too needs to be cut down to give it room to swing... A really good one is to grind a 15mm hexagon on to the socket so that a ratchet spanner can be applied... Again, it would need cutting down to give it adequate swing.

Then, once the fixing nuts are off the motors will slip out and there's just enough room to remove them...

James, two relays must operate for slow speed. The middle C/O relay and the LH relay from memory..

A good tip is to have copies of the wiring diagram and highlight the wiring and operated relay contacts for slow and fast operation. I believe there may be a post by Clogzz on here where that has already been done but it does make it clearer.

[elma]

Thats a shame, fan removals beyond what I can do at the moment.

Still need to track down the cause of the relays getting the signals at the wrong time.
I think I've made a mistake and will recheck them.
It should be lhs on only for low speed and all 3 on for high speed.
RHS and middle share an earth so can only come on together.

I must have observed 1 on then 1,2,3 on separately rather than 1,2 on then 1,2,3 on together like I remember.

I wish I could get to the temp sensor and bitron. I actually have no idea where the thermostat is on this engine and have a feeling this will be as futile as trying to reach the pressure regulator was.

[myglaren]

Is this any help James- from Simon's blog here.

[elma]

Massive help, I must be looking for 9,10 or 11.
No wonder I couldn't see it, this will be interesting.

[CitroJim]

Steve, that's a useful diagram! Thanks for posting it up

In that diagram Item 10 is the brown Bitron sensor, 9 is the blue over-temperature light sensor and 11 is the green coolant temperature sensor used by the engine ECU...

James, why don't you come and see me one weekend and get all these jobs sorted here where both the necessary tools and experience reside to do them I may even have some suitable fan motors if need be...

This might be a way of reducing the stress I'm sensing you're feeling over this... We could do your pump too...

[myglaren]

^ Swiped from Simon's blog so it is he who deserves the thanks- I remember vividly his trials and tribulations with it.

[CitroJim]

^ Swiped from Simon's blog so it is he who deserves the thanks- I remember vividly his trials and tribulations with it.

Yes, but you recalled it and took the trouble so you are entitled to thanks too Steve!

[elma]

Certainly will Jim, issues will change but getting the o/s fan out will be far less painful with your help.
Not sure when I'm visiting alasdair this weekend and brothers wedding is weekend of 8/4.

I think I'm ok on the pump, pipe and clips are in the post.