Unidentified Non Factory Wiring...

[bacardincoke 42 1 Cars]

I've no experience with automotive wiring, but I'd like to pick up some of the basics, hence what are probably some obvious questions!

 

I've found a selection of different non factory wires coiled up behind the dash.

 

All of them have been snipped off whatever it was they connected to at both ends so fingers crossed they're just dead weight and not interfering with anything.

 

There's stickers on the glass for a 'Sterling' immobiser, which is definitely no longer there, so that may account for some of the left over looms.

 

There was also a seperate small black box marked 'Foxguard', which I believe was an alarm, but again that's no longer working (the insides are fried) and any wires from it are also snipped off / dead ends.

 

Below are images of a third unknown item, it's a Hella relay that's been wired into what I think is part of the ignition loom.

 

That's possibly still active. I've tried to photograph it for you as it's difficult to explain in words and I'm hoping someone may recognise the white and red factory wires involved, maybe also make an educated guess what it's there for?

 

In one of the images I've marked numbers against each of the 4 x relay terminals and a corresponding number elsewhere to show you approximately where it connects.

 

I'm guessing here, but does 1 go to a red 'Live'?

 

3 heads off to a 'Negative' terminal block on the side of the steering column, out of shot.

 

The white factory wire has been cut and 2 and 4 of the relay inserted.

 

Cheers.

 

 

 

 

 

 

 

 

 

 

 

 

 

[DamirGTI 342]

I don't have experience with the immobilizer wiring on a 205's .. so can't help with that .

 

Wiring identification by color is kinda hard and often misleading , while red wires "usually" mean positive/12v it isn't always the case ..

For precise wiring identification , you need to go by numbers and letters , which are written black onto the each separate wire on the insulation .. say like - 14B , it can be just the number or the number and letter combination , it depends ..

 

As for what those relays do , you can simply unplug them one by one and see what stops working on the electrical system with them unplugged .

 

D

[SootySport 23]

Look at the oe loom wires and if wire has been cut and joined into the aftermarket wiring, disconnect it and rejoin to the corresponding colour wire that’s in the oe loom.  Most wiring coming from the blue crimp connectors is not original.  I would disconnect the lot in one go and be left with just the oe loom which is less confusing.  As said you should see numbers on each wire which will help re-connecting like for like colours.

Good luck.

[jackherer 543]

I think that might be connected to the starter motor.

 

The simplest test to confirm that is to put the key in, turn the ignition on then hold the relay and see if it clicks when you turn the key to actually start the engine.

 

If it does go to the starter it has probably been installed to mask a wiring problem elsewhere so if you remove it you might have to fix the original problem which is likely to be intermittent.

[bacardincoke 42 1 Cars]

Yep, I think that's the way forward... I'll try and eliminate different possibilities one by one.

 

Cheers everyone, will keep you posted!

 

[bacardincoke 42 1 Cars]

Difficult to describe in words, but here goes... The red wire marked '1' on the image becomes live when the ignition key is turned its farthest, i.e. when starting the car.

 

The black white '3' is an earth.

 

Between them they activate the relay momentarily when the car is started.

 

The remaining two wires to/from the relay are in reality the single white wire cut in two. That wire is part of the cars original loom from the ignition.

 

If the white wires are reconnected to one another (bypassing the relay) the car will start as normal, but if they are disconnected from either one another or the relay the ignition is totally dead.

 

The relay is therefore momentarily reconnecting, then disconnecting what was originally a permanently connected wire.

 

It's a 4 spade relay so there are no spare terminals that may have once had other wires.

 

Independently the cars starter motor and solenoid have just been replaced as the existing ones, which seemed to be the 1989 originals finally packed up after getting temperamental. We tried all the alternative causes such as wiring, earths etc. before doing so.

 

The car now starts perfectly every time.

 

The relay has been removed and wiring restored to original with no obvious impact on anything else.

 

As mentioned above, could this have been an attempt to bypass or mask a starting problem?

 

The car had both an alarm and a separate immobiliser fitted at some point, they too have been removed before my ownership, perhaps the relay was to do with one or other of those?

 

 

 

 

[jackherer 543]

4 hours ago, bacardincoke said:

As mentioned above, could this have been an attempt to bypass or mask a starting problem?

Yes 100% based on this description:

 

4 hours ago, bacardincoke said:

The red wire marked '1' on the image becomes live when the ignition key is turned its farthest, i.e. when starting the car.

 

 

 

Between them they activate the relay momentarily when the car is started.

 

As I said before don't be surprised if it fails to start again at some point, it's a very common 205 problem. Because there is no relay as standard the voltage from the battery has to go through the fusebox, ignition barrel, various multiplugs and a few meters of wire before it reaches the starter solenoid and every small bit of resistance at each point in the  circuit can add up to a significant voltage drop.

[bacardincoke 42 1 Cars]

Cheers... all that makes perfect sense, I'm just hoping it was the previously dodgy starter and/or solenoid that prompted the relay solution and not something else!

 

Was the relay giving the starter a voltage boost to overcome loss elsewhere?

 

In light of what you've said it's possible the drop in voltage wasn't helped by this... When I got the car the battery had previously been relocated to the boot, and was a heavier duty item to what I'd expect a standard one to be.

 

The work appeared to have been done correctly and used bought in parts, it's since been taken out and a new battery's back under the bonnet.

 

I'm guessing the length of (and the gauge, it was pretty hefty) the cable from the boot was bound to have also been a big drain on the voltage... maybe even helped do in the starter?

 

 

[AaronMountford1990 0 1 Cars]

18 hours ago, bacardincoke said:

Cheers... all that makes perfect sense, I'm just hoping it was the previously dodgy starter and/or solenoid that prompted the relay solution and not something else!

 

Was the relay giving the starter a voltage boost to overcome loss elsewhere?

 

In light of what you've said it's possible the drop in voltage wasn't helped by this... When I got the car the battery had previously been relocated to the boot, and was a heavier duty item to what I'd expect a standard one to be.

 

The work appeared to have been done correctly and used bought in parts, it's since been taken out and a new battery's back under the bonnet.

 

I'm guessing the length of (and the gauge, it was pretty hefty) the cable from the boot was bound to have also been a big drain on the voltage... maybe even helped do in the starter?

 

 

If a bigger battery had been put in, had the audio wiring been messed with? Sounds like someone could have uprated the audio system and needed a bigger battery to cope with the extra demand?

[bacardincoke 42 1 Cars]

That's possible, I hadn't considered that. There was no radio in the car when I got it so you may well be right as I've no idea what was in there before.

 

It didn't bother me particularly at the time, as I've a few old 80/90's sets in the loft for a couple of other old cars I have. I didn't realise until later that original Philips or Clarion sets seem quite rare and can fetch strong money in good nick.

 

The speakers are still in the doors / C pillars though and seem to be the originals, but are in very poor shape.

 

Touch wood, so far it's looking like we've fixed the problem and tidied up all the extra wiring that went with it... nothing like tempting fate! 

[davemar 16]

In my car the resistance in the ignition key switch had gone up just enough to not allow enough current to kick the solenoid into life; so I fitted a relay between the key switch and the solenoid and it starts every time. Well it did for several years up until I last started the car about 18 months ago!

 

[bacardincoke 42 1 Cars]

Interesting to know, cheers... I suspect even more now that's what was being attempted here also.

 

The work was done by a previous owner, so I can't say if it was the same cause that prompted them to do it, or even how long ago it was done.

 

It seems to have worked up to a point as the car started fine for quite a while then began to get worse.

 

I'm beginning to get my head around the whys, but I'm wondering was it also putting undue strain on the starter/ignition system?

 

Perhaps my starter was on the way out anyhow (as it appears to have been the 1989 original), or did this workaround help it along... be useful to know if nothing else!