Hi chaps - I have stumbled across a small problem which I cannot myself solve easily.

Below I've posted a picture of an item I have discovered in the wiring loom. It is a small cylinder approximately 8mm diameter and 8mm long with one input and one output. On it is written P600G MIC. It is connected in series within an orange wire which I know comes from the lighting relay circuitry up to a small connector (which maybe the headlight connector) my wiring diagram is not too clear regarding colours. It looks like it is a small part of what looks like an aftermarket alarm/immobiliser system as there are numberous other rouge wires around which are not documented.

My question is: could this be a transponder? If so, could I simply chop it out and reconnect?

The other rouge wires may present me with a problem as a later date... I'll have to cross that bridge when i get to it.

Many TIA

[Edited on 16-2-05 by Hellfire]

Looks like a diode... (but could be ANYTHING!) can you tell me what the full number is on it?

Cheers,
David

[Edited on 16/2/05 by flak monkey]

P600G MIC is written on it... any help?

Well my googling has brought it up as a possible

general purpose rectifier diode

INFO

FULL LIST

any help?


Cheers

G

Fairly meaty diode - must have been there for a reason (to protect something). But installation looks possibly aftermarket so may be part of an alarm - possibly part of the system that allows the alarm to flash the lights or something?

Hard to tell without knowing where the other side of it goes to! Take it out and see if everything still works. Or leave it in there!

Er, hope that helps,

Liam

It's a high current diode.

Probably been used as a 'blocking' diode. i.e. stops current flow in reverse.

If it's been part of an alarm system with lights wiring, it will have been on the 'headlamp flasher' circuit of the alarm.

I was right then...

If its in the relay circuit for the lights it probably allows the relay to be held open or closed, which makes me think you may have a momentay switch for full beam lights? Ie you press it and it returns to the original position, then press again to turn off?

Long while since i did electronics so i could be wong...

Look in my pic archive at the immobiliser thingy. The diodes allow the relay to stay 'on' if the dongle is removed, should give you an idea what i mean.

Cheers,
David

[Edited on 16/2/05 by flak monkey]

Muchos grassy arse chaps!! Seems like a removal is in order then...

As everyones said Hellfire its a diode if you think of it as an arrow with the white line being the point of the arrow that means that current will travel in the arrows direction but not the other way.

So if a connection was made after the arrow no current would flow on its other side.
As Rob and Liam said it'll be headlamp flasher.
Cheers,
Bob

Just to try and explain what it could have been.

i once fitted a Harry Moss alarm (aaarrrggghhhh i hear you all shout). It had single wire output to flash the headlights if it was triggered. The trick at the time was to smash the headlight, short the bulb, blow the alarm in the process and it ceased to work, leaving the scum to break in without the siren going off. To avoid this i decided to feed the wire to each indicator circuit (this way lights flash at the back of car as well). i diode was fitted in each wire so that in normal driving, whem right indicator was selected it didnt send a feed to the left one and vice versa.

Hope this helps. Oh - and the diodes looked very similar to your pic.

Darren.

Thanks for those reply's - they have helped me no end... I have discovered what most of the terminals and connectors are for now but there are 4 that I'm lost with.

I think these too are aftermarket as the taping is not as good as the rest of the loom... If I tap them back to source and chop them out all should be ok shouldn't it?

You shouldnt have any probs with that at all Hellfire.
Cheers,
Bob

If its a diode wired in parallel across a relay then don't remove it from the circuit relay is in. The diode allows the relay to switch of properly, without the diode the relay is likely to stick on.

If your removing the alarm then remove it with the alarm, other wise leave it be.

[Edited on 18/2/05 by clbarclay]

[Edited on 18/2/05 by clbarclay]

The diode was probably wired across the coil of the relay. It stops back EMF from the coil affecting other circuits. It wouldn't make the relay stick on (high current relays need a capacitor across to limit this not a diode)

Marcus

If the relay is on its own (which i admit is never likely to happen in a car) then there is no wear for thge back EMF to go, hence the relay sticks on.

Where there are other parallel ciruits, then the back EMF is earthed via the other circuits. The diode offers a cuircuit of very low resistance so that there is practicaly no effect (no noticable effect on the other circuits).

I have no experiance of high current relays, the majority my knowlage is base on 12v circuits, the capacitor bit is new to me. Can you produce a basic circuit diagram of how the capacitor is itergrated with the relay.

I was going to trace all wires (from the alarm) back to source and untwist the wires... should take all of 3 seconds.

Then they wonder why the alarms get false reading and are triggered?

Off topic a little - I fitted my own home alarm over 10 years ago. I got lots of good quality PIR's and contacts for the doors and windows... fitted is myself, not one false alarm in that period. My neighbour got an all singing and dancing one (recommended by insurance co.) and guess which one goes off at inconvenient times regularly?

Clue: not mine... but I got/get no discount from the Ins. Co. .

A friend of my brother had a mk2 fiesta, had an alarm fitted (not sure why, the car was largely anti rust paint and slaped on filler), the alarm was so jumpy that you could lean out of a second floor window and set it off..

Needless to say it didn't last long.