Fan Relays Behind Grille

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
P616VKX
Posts: 128
Joined: 01 Feb 2011, 23:04
Location: Essex
My Cars:

Fan Relays Behind Grille

Post by P616VKX »

Hey guys,

I've played with my fan relays, but they wont come out. One of them actually threatened to take the innards of the plug with it! Why are they so damn hard to get out? I broke the three fixings to keep them in place too, along with the cover on the front :(
B564PLC - Red/Grey Renault 11 GTL 'Premiere'
citronut
Posts: 10937
Joined: 29 Apr 2005, 00:46
Location: United Kingdom east sussex
My Cars:
x 92

Post by citronut »

they have probably grown/taken root into place,


regards malcolm
User avatar
CitroJim
A very naughty boy
Posts: 49518
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6156
Contact:

Post by CitroJim »

This is a common problem. What will have happened is the heavy current flowing through the relay pins will have overheated the pins and they'll be almost welded in. You'll most likely find the relay base has melted around the pins and this will have caused the 'weld'

Clogzz has a lovely photo that graphically demonstrates what happens. Normally a bit of judicious fiddling gets them out...

Those relay bases are a dockyard job and a half to replace although it can be done with a lot of Malcolms's PERCYWHATSIT...
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
Clogzz
Posts: 2115
Joined: 15 May 2005, 18:04
Location: Australia
My Cars:
x 36
Contact:

Post by Clogzz »

lovely photo
Image
2002 C5 2.0i AL4 230,000 km 76372389
P616VKX
Posts: 128
Joined: 01 Feb 2011, 23:04
Location: Essex
My Cars:

Post by P616VKX »

In response,

I've replaced/played with/changed all relays in the compartment behind the grille... Still no improvement. The big fan started up off of a sudden when I was prodding one relay with a screwdriver taking a small slice of my hand with it...

The relays all looked in good nick, so I've kept ALL of them anyway. There was no melting and no welding in, only a tight fit cured with some lube.

But still, no cigar. O/S fan wont come on with the Air Con on and the N/S Fan comes on in blips for two or three seconds when the engine temp goes over 100...

Taking the plug off the thermostat does nothing to the OS fan, only the fast one.

Any more ideas before I start using a hammer?
B564PLC - Red/Grey Renault 11 GTL 'Premiere'
User avatar
Clogzz
Posts: 2115
Joined: 15 May 2005, 18:04
Location: Australia
My Cars:
x 36
Contact:

Post by Clogzz »

Don’t get the hammer out yet, read this topic first: :mrgreen:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=31403
2002 C5 2.0i AL4 230,000 km 76372389
P616VKX
Posts: 128
Joined: 01 Feb 2011, 23:04
Location: Essex
My Cars:

Post by P616VKX »

Clogzz wrote:Don’t get the hammer out yet, read this topic first: :mrgreen:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=31403
None of it makes any sense because I'm electronically illerate!

All I can see is that my relays are all black, not two green one black.

And neither of my fans work on slow speed. Only the Fast Fan on Fast Speed.
B564PLC - Red/Grey Renault 11 GTL 'Premiere'
User avatar
Clogzz
Posts: 2115
Joined: 15 May 2005, 18:04
Location: Australia
My Cars:
x 36
Contact:

Post by Clogzz »

There’s no need for electronic literacy, it’s ordinary electrics … wire pulling. :)
It now looks like the hammer will come in handy to gently tap around the fan motors.
They may have worn brushes and tapping around may reseat them.
If one motor turns much more loosely by hand than the other one, it has worn brushes.

There’s no slow fan or fast fan, they both always have to do the same speed, meaning both slow or both fast.

The green relays, I think have four pins, to use at the top only.
The black ones have five pins and can be used all around, with the fifth pin doing nothing at the top.

Hammering fix in this topic, third last post:
http://www.frenchcarforum.co.uk/forum/v ... p?p=261591
2002 C5 2.0i AL4 230,000 km 76372389
P616VKX
Posts: 128
Joined: 01 Feb 2011, 23:04
Location: Essex
My Cars:

Post by P616VKX »

Right, another update! I looked at the diagram and saw that things aren't too difficult!

I put a black relay into the socket for the drivers side fan and all the same, until I took the top off of the relay and pushed on the NS towards the OS and then both fans sprung into life at low speed. However, with no pressure against the switch in the relay, nothing happened.

I wedged it with some cardboard and it worked, but the problem was that the fans were running on low constantly, ignition on or off. So this is an issue. But at least both fans are running and working fine, just the relays aren't working properly.

Now, what is my next port of call? Getting the correct relays in there to see if that makes any different or should I be looking at the wiring for the Drivers Side Fan?

This is driving me absolutely mental... I'm sure I've had enough... Lol.
B564PLC - Red/Grey Renault 11 GTL 'Premiere'
User avatar
Clogzz
Posts: 2115
Joined: 15 May 2005, 18:04
Location: Australia
My Cars:
x 36
Contact:

Post by Clogzz »

If I understand that you have taken the cap off the top right relay to close it, then it’s normal that both fans run at low speed even with the key out.
It also means that the relays, the fans and the thick power feed wires are good.

The fault is that the top right relay coil isn’t being fed or switched when the aircon is turned on.
The usual cause is a 5 Amp fuse in the under-bonnet fuse box, but don’t know its name or number.

With a test lamp or multimeter, check for 12 volts on the top connector of the relay socket, and also on either the left or right one, but don’t remember which one.
If the socket is twisted or mangled; left, right and top mean whatever parallel connectors, not the blackened one that sits at 90 degrees to the others.
The two voltages must always be there, even with the key out.

Enjoy a good fiddle, you’re obviously progressing. :mrgreen:

Image
2002 C5 2.0i AL4 230,000 km 76372389
P616VKX
Posts: 128
Joined: 01 Feb 2011, 23:04
Location: Essex
My Cars:

Post by P616VKX »

Well... Played with the BiTron ECU today in the Fusebox by the Battery... And that made both fans work again as they should, but only for a short time.

Should I start looking in the direction of the BiTron ECU/Relays?

Stu.
B564PLC - Red/Grey Renault 11 GTL 'Premiere'
User avatar
Clogzz
Posts: 2115
Joined: 15 May 2005, 18:04
Location: Australia
My Cars:
x 36
Contact:

Post by Clogzz »

The Bitron itself is very unlikely to be faulty.
The plug may have bad contacts that are easy to clean.
Beware of the spring clip holding the Bitron plug.
Use sticky tape or something to prevent it from escaping.
Don’t put the clip back on until you’re sure that you won’t have to go back there any time soon.

Between the fuse box and inner wing are two black covers with two 40 Amp fuses for the fan motors.
These fuses are well placed for fireworks, :shock: so put the caps back on after checking.

Next to the battery is a connector going into the inner wing.
It has a sliding latch and several Bitron wires pass through there.
Slide a few times to clean the contacts or open to clean inside.

In front of the battery is a dangling three-wire plug and connector.
They’re the fan control wires, so check the connections for tightness and battery spillage.

Image
2002 C5 2.0i AL4 230,000 km 76372389
P616VKX
Posts: 128
Joined: 01 Feb 2011, 23:04
Location: Essex
My Cars:

Post by P616VKX »

Hi there,

I've come to a complete loss with this...

5 days until I drive 400 miles and still no cigar...

I've switched the relays back and forth just once more (Probably 50 times) to make sure I haven't made a mistake, I haven't.

I've cleaned the two 40a fuses (Big orange ones), and anything that looked like them, with no improvement. I can't find a three wire plug under the bonnet and that picture seems a little irrelavant to my car. My fuse box is bigger and has an ECU with a 20-30 pin connector bolted onto the top of it.

So, whilst at this loss, is there anything else I can try before I take a match to the damn thing?

I'm eager to find this plug to see if I'm going mad... But I don't think I am.

Stuart.
B564PLC - Red/Grey Renault 11 GTL 'Premiere'
User avatar
AndersDK
Posts: 6060
Joined: 21 Feb 2003, 04:56
Location: Denmark
My Cars:
x 1

Post by AndersDK »

P616VKX wrote:So, whilst at this loss, is there anything else I can try before I take a match to the damn thing?
Yep try a canister of petrol, that will help for sure :lol:

Seriously - there are a couple of other common things that may prevent the fans running.

a) the fans themselves may be faulty. If one of them is defective, neither of them will run in lo-speed mode.
Then only one will be running in hi-speed mode.

b) the "Clogzz problem" pictured may have a nasty variant in that the burnt female spade connector no longer have electric connection to the cable its crimped on to, because the hi temps have caused oxidation of the cable.
The cores of the wire is even sometimes seen completely burnt out, literally crumbling if you try cut the wire back for a new spade connector.

The common solution is to "call a friend" who knows the ins & outs of car electrics.
Anders (DK) - '90 BX16Image
P616VKX
Posts: 128
Joined: 01 Feb 2011, 23:04
Location: Essex
My Cars:

Post by P616VKX »

Both fans will run in slow mode if one of the three relays is opened up and the switch inside is closed. They'll run all day with that, but they don't turn off with the ignition!

Both fans run fine, it's not the relays... Power is getting to both of them without issue.
B564PLC - Red/Grey Renault 11 GTL 'Premiere'
Post Reply