Can anyone tell me what this is and what it does!?

Post by **petefarrell360** » 18 Jan 2005 12:45 am

Ok, I've been fiddling about a bit more than I usually get time to do, and while trying to find solutions to problems and while hunting for wires I came across this little piece of kit.

The disassembled version!

Now, it is located here (this is quite a large photo file, so I've provided the link)
http://www.farrell17.freeserve.co.uk/Pa ... %20Bay.jpg

It's original, as it is on my other cars! It is normally taped up, I removed the tape out of curiosity, it is joined on two spade connectors, however, I wondered whether it may have been the reason why I wasn't getting power further along on another part of the wiring, so tested it with the mulitmeter, but it doesn't seem to let a current through, doesn't matter which way + and - are. Swapped it for one from a spare, still no current either side of it. I don't know where the wire goes or what it is for, it is brown BTW. It's probably something simple that I've not latched onto, but obviously, not knowing what it controls, or what it's called, finding info on it in Haynes, or any other means is somewhat difficult.

Any suggestions please?!

Pete

Post by **Chris_C** » 18 Jan 2005 04:20 am

It's a diode Pete, but whats its for I'm not sure.... I'll have an investigate. What you should find is it only lets current through one way (when the stripe end is at a lower potential to the non stripe end, i.e. a lower voltage)

I'll have a look as to what it's being used for

Post by **5lab** » 18 Jan 2005 09:56 am

brown wires are ground.

Post by **petefarrell360** » 18 Jan 2005 10:14 am

Cheers guys, I couldn't get any current to go through it at all with the multimeter either way! I'm now very interested it know what it's there for and whether this diode is working.
Pete

Post by **huskyracer** » 18 Jan 2005 12:49 pm

Hi pete, the diode (or any diode) needs 0.6v before it will let anything through,so if you resistance test it with a meter, the meter test voltage may not be high enough to make the diode 'work' if you see what I mean, This is why some multi meters have a diode test function
cheers
Iain

Post by **foggyjames** » 18 Jan 2005 02:28 pm

Pete....have you ever heard of "if it ain't broke..."?!

cheers

James

Post by **wjp01908** » 18 Jan 2005 04:34 pm

Hi Pete

The only diode in a brown wire I could find in my wiring diagram was for part of the foglight wiring for Austrian and Swedish cars - I assume that all the wiring looms for a particular model/year were identical, with different bits plugged in to meet differing country`s lighting requirements. In that case probably not needed on UK spec cars.

Somebody with a better grasp of wiring diagrams than myself will probably be able to tell you what it does. They make my eyes go all funny.

Will

Post by **foggyjames** » 18 Jan 2005 04:50 pm

There will be diodes all over the wiring for the car - but most of them won't be shown. Most wiring diagrams are fairly useless for this kinda thing - but showing everything down to component level would be a nightmare to read! Best to think of most wiring diagrams as block diagrams, which are usually more appropriate!

cheers

James

Post by **redline** » 18 Jan 2005 05:05 pm

You could be right Will (as usual )we checked my car while I was there and mine dosn't have one , Pete thought it may be to do with front fogs as his dont work and my car dosn't have any (hence why I dont have the diode )

Post by **petefarrell360** » 18 Jan 2005 06:15 pm

Hi Will,
That as Redline says sounds about right, good work! My fog lights aren't getting any power at all, and as the brown wire heads off over that side of the car, and fogs have a brown wire, I made a loose connection for the two in my head, that possibly it was related.

Cheers Huskyracer, I only use the basic functions of my multimeter, due to the limited knowledge I have, so I'll try that one, cheers!

James, my fogs are broken, well they don't work, so I'm in the process of investigating why they aren't functioning, and I'm an inquisitive person, so once I've found it, I want to know what it is, how it works and if it's actually working!

Pete

Post by **foggyjames** » 18 Jan 2005 06:33 pm

Ok....regarding the fogs...start at the fuseboard, and work forwards until you lose the 12v feed - both in the 'power' and 'switch' (low current) side of the circuit. Try manually exciting the relay, and see if that makes them come on. Methodical troubleshooting is the order of the day, although by the sounds of things you're quite good at that as it is!

cheers

James

Post by **petefarrell360** » 18 Jan 2005 06:45 pm

Cheers James, I've started that route, though as the fuse is in the auxillary fuse box, it makes tracing things a tad more difficult. I've only been messing with it when I've had a few spare minutes anyway, not starting out to fix it there and then! I can actually hear the relay when I turn the switch on, (BTW I do have the ignition and headlights on while testing the fogs!) however would a relay make a noise if it was working?
Pete

Post by **foggyjames** » 18 Jan 2005 06:57 pm

When you say a noise....a click? If it clicks, it's almost certainly working. In that case, focus on the power side at first - assume the switching is working. The grounds by the lights may well be a favourite - maybe being so low in the car, the grounds corrode?

cheers

James

Post by **petefarrell360** » 18 Jan 2005 07:17 pm

Cheers James,
Yeah the relay noise is the muffled click, similar to the main beam of headlights relay. I can't find any power anywhere near the lamps, but corrosion is a good suggestion to investigate. I understand there's a bullet connector style join somewhere in the middle of the lights which sometimes fails, mainly due to corrosion, somewhere near the front valance, possibly covered by the sump guard, think I saw a trace of the wire the other day. I should be under there tomorrow sorting the speedo cable, so I'll check that while I'm at it!
Pete

Post by **petefarrell360** » 18 Jan 2005 10:26 pm

Ok, traced as much wiring for the fogs as I could, right back to the battery on each. I can put the multimeter on the end of each connectors near the fogs, and manage to get a current to the battery connectors, so ground is ok and power should be. Switch is definitely working, makes the relay click, so surely, could it be the relay, if so, which one is it and where is it? Being on my own when looking at it, I can only hear the click from inside, or at best with my head out of the door to operate the switch! Cheers,
Pete