Finding Solenoid Wire #46

[dch1950 37 1 Cars]

I've had my 1.6 for 13 years now and it has been fairly trouble free until the last few years, when starting has become a worry. Initially I had a knackered ignition switch, that I replaced and in doing so got in a mess with the immobiliser hack wiring - you know the sort, all insulating tape and wrong guage wires. Battery going flat has also been a problem because in the last 12 months I haven't used the car much so it's sat there on the drive. Still, that aside, I've been using it more this year and blow me - I'm into a real clicky starter session now. Will it turn over/start or not.

I've researched those topics dealing with this problem and came to the conclusion that my immobiliser was probably going to have to be replaced, but that's a seperate job now.

My problem is almost certainly related to poor connection(s) in the solenoid feed wire circuit, so I set about tracing wire #46 (light blue). I read Anthony's thread reply on the 2 plugs on the driver side and have been unable to locate the wire to the solenoid. Picture 1 below shows the ignition barrel o/p wires and seems to agree with the accepted wiring. brown plug having the +12v supply from plug MR on the fuseboard, and the white plug wired as follows yellow/red - ignition (pos'n 2 of ignition switch), orange/white - starter feed, then the 2 green wires - accessories feed (pos'n 1 of switch)

 

 

 

The o/p wires of the white connector going back to fusebooard to plug BA (see picture 2)

 

 

 

following the circuit schematics in Haynes (diagram 1b), the solenoid wire - pin3 of connector BA, is connected to plug D pin 1 (a light blue wire) - detailed in Picture 3.

 

 

 

- is this wire #46 ? Haynes says it is - but this wire goes onto a (brown) under bonnet plug (I think) that also connects to the tachymetric relay (wire 46b), and also the ECU (start signal ?), The solenoid wire at ignition switch end being white.

I seem to be missing something here as my end goal is to make a single feed to the starter solenoid. So which wire needs to be cut and replaced with the new single feed (to the solenoid) ?

 

If anyone has experience of this, I would be grateful for some assistance.

best regards

Dave

 

 

 

[Ryan 99]

The wiring diagrams in the Haynes manual aren't the best. They're generic diagrams rather than being for any specific model, and are mostly based on early 205s. There's quite a bit that doesn't match up with the wiring of a phase 2 model - in particular they show the tachymetric relay in the engine bay like is was on phase 1 cars.

 

Looks like you've got the correct wire though. From the ignition switch it goes into the fusebox at pin BA3, out via pin D1, then through the brown multiplug near the gearbox to the solenoid. Later cars have the tachymetic relay under the dash, so I assume wire 46b splits off somewhere inside the dash.

[dch1950 37 1 Cars]

Hi Ryan,

been a while - how are you? So the ecu and tachy relay connections are before the fuse box return to plug BA.Logical as the ECU and tachy relay are under the drivers side dash/footwell. Most threads talk of the solenoid wire being in the drivers foot well and say to replace the light blue wire to the solenoid. But there isn't one there.- it's a white wire (from the 4 way to the fuse board at least). So presumably I can check the cranking voltage both at the fuseboard and at the solenoid connector to verify a duff #46 connection between those points. The rest of the fault diagnosis is not so problematic - if I have 12v to solenoid while trying to start - then solenoid is either gone or the starter is on it's way out. If not, then I need to make a direct connection from the orange/white pair at the white connector down to the solenoid. It's a matter of deciding where to make the cut in essence.At the fuseboard or at the ignition lead/plug.

Thanks for confirming the detail.

regards

Dave

[grandos 16]

Just a quick point on this, I had hot starting issues for years on mine, trying different connections at the starter solenoid, replaced the engine side of the loom, replaced the starter motor twice, all to no avail.

When I started tidying up all the under dash wiring I found 3 separate bits of (wrong gauge) wiring spliced into the solenoid wire, presumably from previous immobilisers, I replaced all this with a new bit of (correct gauge) wire and bingo, no issues since. What was happening is that although I always had 12volts at the starter solenoid, it could not cope with the current flow.

 

So my advice would be to visually check every millimetre of that wiring circuit to check there are no horrors waiting to happen!

[dch1950 37 1 Cars]

Hi Grandos,

I agree that immobilser installers are just hack merchants and your suggestions are good. I replaced my fully charged battery in the car yesterday and everyhing was perfect - started first time (everytime). But I still don't really know what is causing the click sysndrome. I like it when things can be measured (being a scientist) and was pleased to find this lovely video on youtube by a guy called Matthew Sullivan. Well explained and practical too.

I did disconnect the starter disable part of my immobiliser as well - just to continue with isolating possible causes. (mines an Auto Watch 239i) and of course the slice in wiring is all thin (higer resistance) but I'm not certain how much of an effect that would have in terms of reduced current in the cranking circuit.. We'll wait and see on that one.

I checked battery post, shunt box connections, etc and will be replacing the +ve connection to the battery, as it's stretched and gone soft, and really might have an effect - either on the battery voltage, or as is more likely poor charging by the alternator.

I will get to the bottom of this particular problem.

regards

Dave

 

[grandos 16]

I think it is just an initial current spike to get the solenoid moving, then the large +ve cable transfers the main current to the starter motor. I have replaced all of my +ve cables with large gauge audio power cables to prevent any other issues.

 

An easy way to check if the fault lies with the solenoid activation wire is to supply the solenoid direct with 12 volts to see if it cranks, if it does the wires (or any immobilisers / wrong doing) are at fault.

 

I had black with a white stripe speaker wire in the solenoid activation wire amongst others which has no thickness to it at all compared to the actual cable, how it never caught fire I'll never know!

 

Good luck with the fault finding.

[dch1950 37 1 Cars]

Hi Grandos, I disagree, a solenoid isn't pulsed - the contactor has to be pulled in during the cranking cycle and released when the key is allowed to spring back. It provides an earth return for the permanent unswitched live on the motor. Equally a solenoid doesn't need high (starting level) amps - it's effectively a high current switching relay -i.e. low current activated to switch a high starting current through the motor to earth. If you read my thread title I was making the point about the "under dash" brown plugs, which I can't find and also the fact that wire #46 - the solenoid feed wire originates from the fuse board (plug D,pin 1) as per my pictures above.

I will be checking the alternator today and battery +ve leads. Lovely weather outside and with the fickle nature of randomness I find this morning that a water main has bust outside the house and my car is sitting in a "lake".

Best get the neoprene suit out then .

regards

Dave

[grandos 16]

Hi Dave, sorry I don't think I made myself very clear! Joys of the written word :-)

 

It's not pulsed but although it is a low current switching a high current, it could still be drawing 5amps (ish just a guess) to move what is basically a massive relay!

In comparison to a lot of signal wires etc in the fuse board that cable has a reasonable gauge to it.

When I ran a separate cable to the solenoid (temporary) so that I could start the car when it was not cranking / clicking I bridged it straight to the battery and it started every time, replaced my cable with decent stuff and I have never had any issues since.

 

Also I would check to see if your engine is grounded properly as this can have a massive effect on starting capabilities! I put a earth strap from the o/s of the engine to the strut top to help with this! (Modern cars have so many more earth points than these little French motors.)

 

Having said all of this mine is a phase 1 but the basic principles are the same they just moved the components about!

Regards Ben

[dch1950 37 1 Cars]

Hi Ben,

I think that the frustrating part of this starting problem is that the circumstances under which it may occur are not "cut and dried". I would then be able to eliminate various items in a progressive manner. With me it's cause and effect - it's a Physics thing I suppose. I can understand high resistance caused by corroded wiring and connectors, But that isn't an intermittent symptom , it's a gradual degradation. Thus logically, having recharged my battery and restored the "starting" status quo then to me it says it's the immobiliser. I have disconnected the start disable circuit ( the hack in wiring - speaker grade ). I will want to measure the increased line impedance with it in and assess the effect on the solenoid activation current. The solenoid latch current is intially high (about 8-10 amps) and decreases slightly as the starter cranks the engine - hence the reference to a latching current and a holding (while cranking) current draw.Today I am going to tackle the earth to the gearbox housing. I would like to think that I should swap out the starter and alternator feed cables - but again, they work fine. Interestingly "dreamweavers" diagram shows wire 46b as the solenoid wire - whereas it's actually wire #46 - 46b is the Tachymetric "cranking" signal wire. Maybe a typo, or a model variation though.

At the moment things are stable - with the exception of my driver side lower dash plastic sitting on the passenger seat, and having to keep the immobiliser out of the way whilst driving. All good 205 ownership stuff.

regards

Dave

 

 

[dch1950 37 1 Cars]

Hi all,

I have been guilty of just dropping into the middle of a "typical 205 problem" - quite common on this forum, and for those of you who maybe don't know what I'm on about this link explains the operation of the starter motor and it's associated solenoid.

 

http://www.cdxetextbook.com/electrical/chargStartLight/start/starterengage.html

 

Wire #46 in our case, being the one between the ignition switch and the solenoid itself. Conveniently coloured blue in this generalised schematic.

Stalled a bit yesterday as Severn Trent were repairing the mains outside the house, so it's all mud and water and not good to be stuck under your car in that.

My battery positive connection is not in good nick so I'm going to have to replace it and get some cables form VWP with ring connectors each end. one for the shunt box and I for the battery to starter cable.

 

Can anyone who's done this tell me the relevant cable lengths for these 2 cables.?

 

I have been researching alternator testing and realised that most of the easy to perform checks at the battery don't really tell you much, I.e. if alternator o/p voltage exceeds the cars supply voltage (around 12.6 v) then there will be a net current flow into the battery and it will charge. However just seeing a voltage in the range 13.5 to 14.5 volts at the battery isn't absolute proof of a healthy alternator.

I've located the engine bay brown multiplug, at last, and no surprises there - it looks pretty cruddy.But given what else runs through this why would it just be the solenoid wire that is doubtful ?

We'l hopefully progress a bit more today.

regards

Dave

 

[Ryan 99]

I did my battery cables using stuff from VWP not long ago. I used 40mm^2 cable for the starter, and the gearbox earth (1m of red and 1m of black was plenty), and 25mm^2 for the alternator and the earth for the inner wing (again 1m each was enough).

Edited May 9, 2013 by Ryan

[dch1950 37 1 Cars]

Hi Ryan,

I wanted to buy ready made (with the ring terminals crimped already). The existing cable are 16mm^2 for shunt box and 25mm^2 for starter - so 40mm^2 is a bit of overkill. Also I don't have a ring crimp tool for cables that big - they are hugely expensive.

That's why I was interested in the exact lengths

regards

Dave

.

[Ryan 99]

Actually now that you mention it I think it was 25mm and 16mm, not 40mm and 25mm.

 

I've got the old cables somewhere, I'll measure them when I get chance later.

[Ryan 99]

Battery -> Starter = 70-75cm
Starter -> Alternator = 35cm
Battery -> Gearbox earth = 60cm
Battery -> Inner wing earth 40-45cm

[dch1950 37 1 Cars]

Hi all,

I have been running the Pug for a couple of weeks no with no click problems at all ( as soon as I utter those words I know what will happen... ). The finger is pointing towards my immobilser - the starter disable circuit wiring.

I've put the lower dash plastic back - MOT due this week and will continue to monitor the situation. I never did locate the under dash brown plugs though ( wire #46 or was it 46b).

regards

Dave