Rad Fan relay connector repair

John Plum · Post by **John Plum** » 25 Mar 2014, 14:25

Q. How should i best go about repair to a rad cooling fan relay connector, with such little room with only front cover off?
The car is a Xantia HDi 110

Seems I have a break at the female connector to n/s relay pin no 5, or the takeoff wire close to that connector.

- Only d/s fan works when disconnecting bitron.
- 12v applied to pin 5 do not spin fans.
-A good voltage supply is found on pins 1 and 3.

Luckily or not, when playing around and refitting the n/s relay, both fans came on briefly, and again when I jiggled the connector around.

Possibly a question for Paul - CitroenXM, as I've read you've come across such problems.

Regards, John.

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John Plum · Post by **John Plum** » 25 Mar 2014, 18:28

I suppose I just gotta get to enough of the wire by pushing radiator forward, maybe removing intercooler... And then try fixing a new female terminal at pin 5 in the old socket, by replacing female terminal at pin 5, if possible OR if not, crimping on a new pre-wired socket.

I'll tackle it when I've gathered a new socket, in case I need it.

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citroenxm · Post by **citroenxm** » 25 Mar 2014, 19:03

You Can NOT gain any access to the back of the relays from the rad side so there is no point in pulling them forward.. unfortunally the only way to do it is to remove the relay HOUSE from its fixing point and Try pulling it as far forward as possibly to get at it. You then idealy need a hand crimping tool and some terminals.. however if theres an internal break in the wire due to copper corrosion it could be any where from the relays back to the control box or to the fan motors depending which wires are broke.

There is a character difference between early s2 and later s2 operations on the fans I have found. By later I think 1999/2000 onwards. Early cars behaved like series ones and both fans should run in slow mode when the air con is on and continiuos... then of course higher speed when the engine needs cooling which is rare on hdi..
then from late V reg I found that just the one fan on the drivers side spins full speed for about 10 secs then stops .. in a regular freqency.. then both fans run for engine cooling reasons.

to be continued when I get on the laptop after.

A hand tool like this one should help... complete with terminals...

http://www.ebay.co.uk/itm/175-Pieces-So ... 20e24fe31b" onclick="window.open(this.href);return false;

John Plum · Post by **John Plum** » 25 Mar 2014, 21:01

Cheers Paul. Great info, I'm really glad I asked!
This is 1999 reg (t reg), I suspect the old mode of function.

Got the crimp tools: I think your suggesting attaching a whole new socket, if the break is close to it, rather than attempt to put in a new terminal to the socket, probably because I can't get the old terminal out in that restricted space.

As it worked briefly when I replugged the relay, and then pushing the socket back on its mount (well, attempting to!), I suspect the break is very near or at the terminal to relay socket.
I think it's terminal 5 , from the testing, which I guess leads to the fans.

Where is the control box?

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citroenxm · Post by **citroenxm** » 25 Mar 2014, 21:11

In a bloody horrid place John,

Its under the Panel beneath the passenger headlight!! Completely hidden away!!

John Plum · Post by **John Plum** » 25 Mar 2014, 22:36

Oh the bitron, yes? Well, hopefully that's not my problem, with pin 5.

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Clogzz · Post by **Clogzz** » 26 Mar 2014, 05:35

John Plum · Post by **John Plum** » 26 Mar 2014, 15:27

Clogzz you're a gentleman.
I'll study these, because I'll need to to solve this efficiently.

Made a mistake in my diagnosis, missing a point: The lack of spin when applying 12 volts to pin 5 suggests a possible fault with either centre relay, fuse or earth. Fuse is checked, OK.

Checked centre relay, and pin 3 was corroded a good deal. Cleaning up and swapping to known good centre relay gave the fault in a dashboard of red blinking cooling light (absent before) So, progress, not solved yet though.

Got all the slack I could on the wires to sockets, and it's just enough, thanks so much to Paul.

Shall take it from here. Study circuits above and re-read the posts I found, before going in armed with a list of tests.

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John Plum · Post by **John Plum** » 26 Mar 2014, 19:01

Having read there's no bitron on hdi's, I wonder if the tests I find apply to an engine ECU-controlled fan system.
I suppose they do.

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John Plum · Post by **John Plum** » 26 Mar 2014, 21:56

I wonder, given that HDI aircon pressure sensor goes to engine ECU (for lack of Bitron), would low pressure affect tests for low speed operation of fans on HDI engines, meaning I should get a pressure test and recharge as necessary, before testing fans further?

Sure, a Lexia is what I need first, I'm thinking.

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Clogzz · Post by **Clogzz** » 27 Mar 2014, 01:07

First test is to find if the nearside relay clicks on when the air conditioning is turned on.
It must do so irrespective of aircon pressure or engine temperature.
Maybe enlist a volunteer to hold and feel the relay while you switch the aircon on and off.

Best wishes.

John Plum · Post by **John Plum** » 28 Mar 2014, 19:23

@Clogzz I feel like I'm in a safe pair of hands! Thanks...

Test Result: N/s relay fails to click with aircon button switched to on; I listened, my volunteer threw the switch, engine running.
- Q. Meaning... ? (Assuming relay is good)
- Q. next test, logically?
- Q. are relay pin tests, both shorting to earth and supplying 12 volts, meant to be done with relay plugged in socket?

I doubt the ambient temperature sensor is implicated in AC and fan behaviour ever - the one in wing mirror;
- mine is reading 12 below on a mild day today; a week ago this same sensor seemed sensible , giving 5 above, but since commencing with fan relay tests and switching AC it has gone stupid.

Cheers,
John

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Clogzz · Post by **Clogzz** » 31 Mar 2014, 10:03

Sorry for the delay, I missed my playtime on the forum.

If the temperature sensors think that it’s less than something like 6ºC, they won’t let the air conditioning start.
The fan motors sometimes have worn brushes and a few firm taps on them can cause the brushes to reseat on the collector.

To find out if it’s a control or supply fault; with the engine turned off and the nearside relay pulled out, short connectors 3 and 5 (top and bottom) of the nearside socket.
That should start both fans at the low speed.
If not, pull the centre relay out and put another 5-pin relay in its place.
The centre relay lets the current pass through pins 3 and 4 to the offside fan when not energised.

Link to the Admiral’s “How To” guide:
http://www.frenchcarforum.co.uk/forum/v ... hp?t=31403" onclick="window.open(this.href);return false;

Best of luck.

Post by **RichardW** » 31 Mar 2014, 12:34

The cooling fan behaviour Paul outlined above is not necessarily related to age - mine is late (Dec 2000) and has both fans coming on together all the time AC is on. I can find no difference in fans or relays, or wiring harness to support the change, but there must be - the wiring diag printed above (which may or may not be relelvant to the HDi where the fans are controlled by the ECU!) can't do that operation, as the change over relay and right fan relay are controlled together. I think...

Clogzz · Post by **Clogzz** » 31 Mar 2014, 13:30

The diagrams are from the 1996 petrol Peugeot 306, well before the HDi.
And yes, the change-over and right fan relays are controlled together:

http://www.peugeotlogic.com/workshop/ws ... fanop1.htm" onclick="window.open(this.href);return false;

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