Citroen XM Forum

The item you have circled in your photo is one of the three relays (not fuses) that between them control the radiator cooling fans, making them run either at low speed or high speed.

My advice is check out the earths first, before investigating anything else. You have so many misbehaving items of equipment, grounding has to be suspect.

It is also possible that the car is suffering from low battery voltage, which can cause relays and electronic units to operate badly, or not a all.

It is common for ageing XMs to need their main battery connectors (the lead (Pb) lumps attached to the battery terminals). These are crimped on, and relax their grip on the heavy duty cables over time. The cable strands also oxidise (turn black) inside the connectors, and cause a voltage drop.

A quick test for poor terminal connection is as follows:
- Crank engine, as if to start, but do not enter a keypad code, so engine will not fire up. Crank for 10 seconds.
- Carefully feel each of the battery terminal connectors, and if either of them is warm (or possibly hot) to the touch, there is a bad cable connection there.
If in doubt, cut off both the old connectors and replace with brass clamp-type connectors. Clean up the cable strands, back to bright metal, when you fit them.

Do the earthing check first, and let us know how you get on - and what engine you have - and the car's RP number (this is painted on the front passenger door post, between the hinges. It will look something like CJ 7165. Alternatively, post up your VIN/chassis number (VF7Y4......something). These will let us look at the correct wiring diagrams for the car, if needed.

ok thanks! like i said i'm a newbie, learning quickly so excuse the ignorance

i changed out three relays behind the lower dash panel on the drivers side, big red one, small black one, and green one. that's done nothing. i guess the interior lighting dimmer is a relay, in which case it's one of those?

OK, i'll get onto that terminal test and earthing points clean.

btw when you say: Crank engine, as if to start, but do not enter a keypad code, so engine will not fire up. Crank for 10 seconds.
not sure what u mean by keypad code?

code on inside of passenger door between hinges 6427
vin: vf7y4td0000td0435

Early Mk2 2.1TD Auto.
Not sure that these had a keypad.

xmexclusive wrote:Early Mk2 2.1TD Auto.
Not sure that these had a keypad.

No keypad!

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edelweiss wrote:HI
Can anyone describe how to replace the fusebox on xm mk2, or is there any resource online where I might be able to find out? Have various intermittent electrical faults:
- indicators not working, instead making interior light come on and making a horrible buzzing sound from under the glovebox
- central locking with fob only closing not opening
- horrible clicking sound sometimes when driving from dash display area
- weird sound from engine fusebox after turning key off
- all lights remain on dash display on when engine turned off (only switch off when i open and close drivers door)
- battery light on when switch interior light on, disappears when light goes off

am thinking fusebox might be key

thanks

Having re-read this, I would advise you to check the Ignition switch is functioning properly, especially that it is breaking the circuits when switched off.

OK, so no anti-theft keypad. There are ways to prevent the engine from starting, and keep it cranking, but I won't ask you to do those . . . even more to go hunting for!

Try starting the engine repeatedly (switch off each time it fires up) - say 6 or 8 times. Then immediately feel the battery connections for heat.

Or just replace them, if they're the original grey, soft-metal lumps. They're a known cause of problems, at some point or other.

edelweiss wrote: i guess the interior lighting dimmer is a relay, in which case it's one of those?

This interior dimmer is a small box that makes the lights go out slowly, gradually, in a couple of seconds rather than at once when you shut the door or start the car.

This box is inside the car (under the glovebox on LHD). As a rule, items serving the internal features don't go under the bonnet. But at any rate, don't replace any of these items before you checked the earths first. Ten units don't go all wrong at the same time. You have to find the part that's common for all of them. That's either the feed or the earthing.

ok i cleaned the earthing points and tested for poor terminal connection nothing doing it's still the same

someone mentioned ignition switch, i guess that's next port of call?

in which case, how do i check the ignition switch is breaking circuits?

something ive noticed is that when i put the key in before turning it the cd changer kicks into gear.

Good to have cleared the grounding and battery connections out of the way.
That remark about the CD unit does suggest there is an IGN switch fault - circuits making prematurely, or not breaking/switching off properly.

John (xmexclusive) is expert on IGN switches.
Is yours marked Simplex around the keyhole?