Starter Signal Wiring

[Tom Fenton 1,542]

Gents

 

Got a 205 in at the moment, that talking to the owner of 20 years sounds like it has almost always had an issue with the typical 205 "clunk" non start.

 

The high current wiring back to the battery is pretty crap so I'm going to renew all that and also the battery clamps.

 

However this can't have always been poor so I'm looking at the starter signal wire also.

 

Now from my memory and looking at the wiring diagram, it seems the starter signal comes from the ignition barrel, through the barrel plug, runs across the car to plug into the fuse board, then comes back out of the fuse board on a plug, across the car to the brown plug under the dash. From there it makes its way out in the main engine harness round the cam cover area and then beneath the inlet to the brown plug near the dizzy. From there a short section back to the starter solenoid.

 

All these plugs for me have got to be contributing to a high resistance somewhere which leads to low voltage at the starter and the annoying clunk non start.

 

For info the starter has been recently replaced for a later type small body starter.

 

Anyway to get to the point.

 

I'm thinking of one of two things;

1) Do away with the link inside the car. Pick the starter signal up straight off the ignition barrel and send it straight out to the starter. I'm aware the SAD earths on this wire so I'd pick that up.

2) Or leave the link over to the fuse board intact. What I'm not certain about is if there is another link within the fuse board that then sends the starter signal elsewhere. But still tee the signal direct to the starter near the barrel.

 

Thoughts welcomed if theres something I'm missing.

[Anthony 1,003]

That sounds about right, having had similar fun belling through the complete torturous starter wiring path in the past trying to find the cause of an intermittent non-start.

 

9/10 the issue is that brown multiplug in the engine bay - every single 205 I do anything with now I get rid of that as a matter of course, accepting of course that there will inevitably be several inches of corroded wiring that will want cutting out too.

 

One thing you didn't mention is whether there is an immobiliser fitted - if so, check the wiring where it's been spliced into the car wiring as it's often less than ideal shall we say.

 

The starter signal doesn't split until the engine loom, where it goes to both the starter and tachymetric relay (on Jetronic models anyway)

[Tom Fenton 1,542]

It does have an immobiliser fitted, but I'm fairly sure it doesn't immobilise anything any more. But I will check that out.

The brown plug in the engine bay is long since bypassed.

My plan is to pull a totally new core in from the ignition barrel direct to the starter with a splice off to the SAD. While I'm there I'll cut the various sensor wires back to good and re-end them as some of the gauges are intermittent.

I'll keep this updated.

[steve@cornwall 100]

I've run a "piggy back" wire straight from the barrel to the solenoid for years without issue.

[Miles 331 1 Cars]

Had the Ignition switch be a issue in the past as well

[pug_ham 244 3 Cars]

When I last had my engine bay loom out on my MP3.1 conversion, I replaced the solenoid wire from the footwell brown plug with fresh wire, the wire I removed looked in a very bad way.

 

The core was black & brittle but the wire to the brown plug inside the car was in a far better condition so I didn't take it any further in.

 

I didn't split off the SAD wire as I have removed it.

 

Unfortunately the car hasn't seen much use since but to date I haven't had any issue with the starter again.

 

g

[Tom Fenton 1,542]

Well I have got further with this.

To be honest the engine bay wiring is poor. The cores for the oil pressure, alternator signal, starter signal all run in the main harness past the place they need to go, to the crappy brown plug, then back to the terminals they end up at.

I've stripped the loom down and picked the cores up and branched them out of the loom near the alternator area. All the copper wire at this point is in decent order! I've crimped new spade terminals on of the heatshrink type to seal them to the wiring.

So far it has worked faultlessly, but the owners reported that it only tended to act up when the car has done a decent run and everything is hot. So I need to get it properly hot and stop in order to test this theory out.

For future reference, inside the main loom that runs from the bulkhead near the lower steering column, in the area of the upper engine mount is where the SAD and other earth points all are spliced into the starter signal wiring.

[Tom Fenton 1,542]

So just to finish off.

 

In addition to the wiring loom I also remade the high current cables from battery to shunt box, and battery to starter/alt.

 

Having done all that the car has not failed to start first time since.

 

Can't decide 100% whether it was the high current wiring that has made the difference to be honest, as the old stuff was in pretty poor condition.

 

I also treated myself to a proper crimp tool for the high current cable lugs. I've always farted about in the past with these either crushing them in the vice or soldering them up. This is far better and a quick neat job.

 

Untitled by Tom Fenton, on Flickr

 

Untitled by Tom Fenton, on Flickr

 

Untitled by Tom Fenton, on Flickr

[welshpug 1,657]

nice job, dare I ask how much they were?

[Tom Fenton 1,542]

£64+VAT, I did think twice but figured I've probably paid £30-40 over the last few years having cables made up, and they are never 100% exactly how you'd want if you can do them on the car.

I need to buy in a stock of lugs now!