cooling fan singular!!!

admiral51 · Post by **admiral51** » Sun Nov 11, 2007 9:16 pm

hi all
ive just aquired a 1.9d lx 1994 non A/C and im having problems with the cooling fan. the fan will work when temp gets to about 95 but not any earlier like i think it should
i have removed the switch on the rad and can get the fan to kick in on fast by bridgeing two of the three pins but nothing on the other for slow speed. have looked at the relay above fan and replaced it with a known good one but still nothing on slow.
the relay is a five pin one that seems identical to the one for the switchover/series for a twin fan set up
any ideas if this is the correct relay and/or is there another relay hidden away convinced looking at relay socket there is only 4 pins with anything in them

cheers colin

MikeT · Post by **MikeT** » Sun Nov 11, 2007 9:24 pm

Hi Colin,

This should help you understand what's going on and what's not

http://www.peugeotlogic.com/workshop/ws ... fanop1.htm

I guess it's the missing link you've been looking for.

though it is for an A/C installed car, not sure how much difference that makes?

admiral51 · Post by **admiral51** » Sun Nov 11, 2007 9:30 pm

hi mike
yes i have that link its for the twin fan setup this one only has the one fan and one relay but can only get it to spin fast(i think) and sensor on rad works cos it cuts in when temp hits about 95 degrees which i think is too high for the fan to cut in normal conditions i reckon it should be nearer 90 but i can only get it to spin at one speed not even sure if it should spin at 2 speeds

cheers for the link anyway it was one i had managed to save

colin

MikeT · Post by **MikeT** » Sun Nov 11, 2007 9:39 pm

Well that write up says they cut in at 97 and stop again at 90 so I shouldn't think yours is much different?

Being non-ac I don't see why it should have two speeds, do you?

admiral51 · Post by **admiral51** » Sun Nov 11, 2007 11:12 pm

MikeT wrote:Well that write up says they cut in at 97 and stop again at 90 so I shouldn't think yours is much different?

Being non-ac I don't see why it should have two speeds, do you?

youre right mike in that sense just seemed odd that my other xantia fans kick in at about 90 and as you know me and mechanics are not best of bedfellows

so just need to be pointed in right direction

it may only need one speed but i need some reasurance

colin

MikeT · Post by **MikeT** » Mon Nov 12, 2007 8:47 am

I know what you mean Colin, better safe than sorry. One thing to note, according to Haynes, the earlier xantia's (up to Jan '97) 'stat's were designed to begin opening at 89 degrees whereas the latter models were revised to 83.

All of them should be fully open at 99 which suggests the fans aren't required until that point.

CitroXim · Post by **CitroXim** » Mon Nov 12, 2007 10:36 am

Right, single fan, no A/C. Very strange only a single fan. Even our little 205D has two. I thought it was only petrol models that had single fans. You live an learn..

In this case Colin, the speeds will be controlled by the sensor screwed in the side of the rad and a resistor for the low speed. In all liklihood, the resistor has gone open circuit.

The resistor often looks like a long aluminium cylinder with two wires exiting from it. This is a favourite problem on the 205GTi whern the fan won't run at low speed...

admiral51 · Post by **admiral51** » Mon Nov 12, 2007 11:17 am

hi jim
would that be the aluminium thing that runs vertical behind the rad on the fan housing and if so are thay expensive/easy to replace

cheers

colin

CitroXim · Post by **CitroXim** » Mon Nov 12, 2007 11:52 am

admiral51 wrote:hi jim
would that be the aluminium thing that runs vertical behind the rad on the fan housing and if so are thay expensive/easy to replace

cheers

colin

Yep, that'll be it Colin, an aluminium cylinder about 3/4" in diamater and about 3" inches long. If it is duff, I have a spare from a 205. If they're the same, the wires end up in a 2-way brown connector.

If you meter it, it should read only a few ohms. I'd check connections to it first as it takes very little crud on a terminal to make a high-current fan fail to run.

It should be a doddle to replace, as long as you have easy access to it.

As an aside, it is one of the most oft asked questions on the 205GTi forum: "What is that aluminium cylinder by the rad?" Som,e 205s had two of them. the other was used for the "dim-dip" headlights once popular in the late 80s.

admiral51 · Post by **admiral51** » Mon Nov 12, 2007 3:48 pm

had a go at cleaning terminals but its a PITA to get at definitely a 2 pin plug but still no joy when bridging main plug only goes full on

looks like rad may have to come out to relace depending on how the resistor comes out

will check on pr-net to check what they say it should be

jim
you may be getting a pm

colin

RichardW · Post by **RichardW** » Mon Nov 12, 2007 4:40 pm

ISTRM that on cars with rad switches to operate the fan(s) you need to bridge all 3 terminals to get one speed, and only two to get another. But then maybe that only relates to cars with twin fans.....

CitroXim · Post by **CitroXim** » Mon Nov 12, 2007 4:54 pm

Hi Colin,

The one I have spare is duff. When I looked at it, the terminals fell apart with corrosion and it is open-circuit.

The Haynes BoL gives the diagram of the single-fan set-up on page 13.33.
Basically, on slow speed, one set of contacts in the sensor make, which earths the fan via the resistor.

On high speed, the other set of contacts in the sensor make, which in turn operates the relay which in turn shorts out the resistor.

So, the only problems can be either the sensor or the resistor. Shorting pins 1 to 3 of the sensor connector plug will give low speed and shorting pins 1 to 2 will give high speed. Check there is a good earth from pin 1 of the sensor plug as if this earth is poor, the relay will still operate for high speed as not much current is involved to operate the realy but it may be too high resistance to allow the fan to run in slow speed. To test this, jump pin 3 of the sensor plug directly to a known good earth.

Hope that throws a bit more light on it Colin

CitroXim · Post by **CitroXim** » Mon Nov 12, 2007 5:26 pm

Colin,

You have a PM...

admiral51 · Post by **admiral51** » Mon Nov 12, 2007 6:38 pm

jim
i may have misinterpreted what you are saying in relation to the earthing of the pins

everybody will laugh now i can tell even from here but...................
when you say pin 1 has to have a good earth and then jump pin 3 to earth what happens when i bridge pins 1+3 as both go to earth

or is this not what you meant

or am i having a really

moment

i need some therapy or maybe a crash course in electrics

colin

admiral51 · Post by **admiral51** » Mon Nov 12, 2007 7:11 pm

if i earth pin 1 on sensor plug (any good earth point) and then bridge pins 1+3 this should make the contact for the slow speed operation i think

its too dark to check now but will try and blow the car up tomorrow morning

colin