LagondaNet

Arnaud · Joined: 26 Oct 2010 Posts: 101

Today I wanted to run the engine and the starter motor didn't stop, I had to cut out the battery to stop it.
I looked at the starter motor and tested directly the solenoid, it works pretty well, I've seen on the workshop manual there was a starter motor relay, does anyone knows where it is located on a 83 ? I can't find it under the fuses box, or was it only on the early ones ?

Do you think it could be the ignition barrel ?

Any suggestions are more than welcome, thanks ! Smile

jonc · Joined: 21 Sep 2010 Posts: 584 Location: Cheshire, UK

On 13277 (1983), I think it is the bigger relay under the fuse box under the bonnet. In my case this is a yellow relay. It is relay 25 on the 1981 and 1982 wiring diagrams.

Relays 24 and 26, which are either side of it on the loom, are both headlamp control relays. It is definitely under the fuse box.

My money would be on the starter itself not disengaging (a mechanical problem), followed by the relay.

Good luck!

Jonathan.

Arnaud · Joined: 26 Oct 2010 Posts: 101

Hi Jonathan,

Many thanks for your answer, do you mean it is the big yellow square relay ?
Because on the workshop manual, 25 is corresponding to a round relay (no color as the picture is in black & white.
Great thanks again !

Arnaud

jonc · Joined: 21 Sep 2010 Posts: 584 Location: Cheshire, UK

Hi Arnaud,

Yes, that is the one I meant. It should be possible to work out if it is the correct one from the colours of the wires going to it. According to my diagram:

48 white-black
49 white-black
50 white-blue
51 white-red
52 brown
53 white-red

Jonathan

Arnaud · Joined: 26 Oct 2010 Posts: 101

Thank you Jonathan, I will check this !

jonc · Joined: 21 Sep 2010 Posts: 584 Location: Cheshire, UK

Its the light blue round one on my car:

Jonathan

jonc · Joined: 21 Sep 2010 Posts: 584 Location: Cheshire, UK

I think the yellow one at the bottom of the picture is a timer for the heated front lamp glasses. It is not on the wiring diagram, and mine is not fixed to anything. Its also yet another thing with altered wiring on my car.

Do you have this on your car Arnaud? Is it fixed to anything?

Jonathan

Arnaud · Joined: 26 Oct 2010 Posts: 101

Thank you Jonathan for the picture, That's what I thought... I don't remember to have seen this round blue relay yesterday on my car...I will check again !
On mine, the yellow relay is fixed near the wall but it is a lhd, maybe the arrangement is different, I'll try to take you a picture next wednesday.

Arnaud · Joined: 26 Oct 2010 Posts: 101

So I looked at the relay...Does anyone know the purpose of this starter motor relay ?

Because if I get it out, the car starts well...There is a wire that comes to a LED (white/red wire), if I let the relay connected but if I disconnect the led, it also start well but if the relay is in place and the LED connected the starter motor will not stop.

I can't find where this wire is coming from, also my relay is not the same as yours Jonathan, I took for you two pictures so you can see where is located your Yellow relay, apparently it is where you have an earth plug !

In red, you have the starter relay and the led

jonc · Joined: 21 Sep 2010 Posts: 584 Location: Cheshire, UK

Thanks for the photos Arnaud - now I know where to mount the yellow timer.

Your wiring is different to mine. From the 81/82 wiring diagrams, I can see that the starter relay operates the starter solenoid. When you turn the key, 12v is applied to wire 53 which goes to one side of the starter relay coil. The other side (which needs ground) gets it from the gearbox switch when it is in park or neutral. This operates the starter solenoid.

When energised, the starter solenoid provides 12v (which arrives on wire 52 directly from the bulkhead battery stud) to the starter motor on wire 51. This is incorrectly labelled on the 81/82 diagrams at the starter as 142 (142 is actually the power feed from passenger fuse 10 to the wiper motor). There is another wire which separately receives 12v when starting - wire 50 - which is the coil boost. This would be for the Opus 2 ignition on the earlier cars which used a 9V coil. My car has the later Lucas 35DM8 'Limb' system and so this is redundant (but the wire is still there).

My guess is that I got the old loom and you got the new one. Your car doesn't have opening rear windows which is the same as mine. I have looked at some more pictures and I can see yours is a US emissions car. Maybe this is the difference? I will see if I can find a US wiring diagram..

Jonathan.

Arnaud · Joined: 26 Oct 2010 Posts: 101

Thank you Jonathan for your help, I will try to check these on mine, it could be really helpfull, our cars are really closed as you have 13277 and I have 13280 so perhaps there were only minor changes...

jonc · Joined: 21 Sep 2010 Posts: 584 Location: Cheshire, UK

Ok. I think I have worked it out.

Firstly, the 1983 wiring diagram still shows a type C relay - which is a dual output rather than the changeover (B) relay. However, you clearly have a B relay, and the relay base shows that it has always been that way. This is not something I can see on any wiring diagram.

What you appear to have is a workaround to allow the B relay to be used instead of the C. This makes sense since it was the only C relay on the car as far as I can tell. Here is the wiring on my car with the C relay, and what I would expect as the B wiring - the boost wiring can't interfere with the starter due to the diode stopping the current reversing along the wire to the starter:

However, this diagram does not correspond to your symptoms.. Here is what I think you actually have:

I don't understand why it would be like this, but if the diode failed closed-circuit, this would cause the relay coil to be powered by the feed on 51 to the starter. This would mean the relay would 'clamp' on as soon as you turned the key. Since the diode is acting like a wire, it would feed the starter if you took out the relay, and if you disconnected the diode, it would work like normal.

So.. I think your in-line diode is faulty (closed circuit) and this is your problem. As to why it is wired like this, I don't know. This would allow the car to be started in any gear..

Jonathan

Arnaud · Joined: 26 Oct 2010 Posts: 101

Thank you so much for your help Jonathan and all your diagrams, I will get a new diode to test it, I tell you as soon as I get one
Thanks again ! Wink

Arnaud · Joined: 26 Oct 2010 Posts: 101

Yesterday, I finaly had time to test it with a new diode, it changed nothing...I can't explain myself the purpose of this relay...

jonc · Joined: 21 Sep 2010 Posts: 584 Location: Cheshire, UK

Hmm.. strange. My diagram is not correct then.

The relay is important - it is there to ensure you can't start the car in gear and drive it straight into a wall! Be careful as yours may start in any gear selector position.

Is there evidence of the wiring being altered? I have discovered that my car also has a diode, but it is at the other end - next to the vacuum control relays where the coil is, and it is on wire 49 - not your white/red one. This is not on the 1981 or 1982 wiring diagrams and I don't have a later one - it turns out my 1983 USA diagram is actually 1982.

Is there a 1983 wiring diagram? Does anyone have a copy?

Jonathan