Its starting itself!!! Help Please

[StuRox]

Well, now my Disco 300 TDi is now starting itself! Quite a change from the threads of ‘not starting’ recently!

As soon as I get to stage 2 of the ignition it starts to turn over, and even when the engine is running its still turning over the starter motor.

I have pulled the spade off the started solenoid, to stop it starting, and then have ran a 12v live to the spade, and this turns over the starter motor fine, so can rule that out.

After searching the forum, I found someone else had a similar problem, and that was down to the ignition barrel – well mine was getting a bit stiff with the key, so thought I would replace that, and still no cure.

In the cold spell, it wouldn’t actually turn over, so I did think there was a problem with the Starter Motor, but as I have mentioned, that turned over fine with the 12v live direct from the battery, so I made up a push button start to get it going in the cold, now I am again using this to start given I have had to remove the original feed from the ignition.

Any idea’s on what to try next?

It must be something simple, as I can leave the gear lever in ‘Park’ and it won’t turn over and the glowplug light stays on to warm, but leave it in park, and turn to stage 2 of the ignition and the glow plug light goes out straight away and will try and start the car without the need of turning the key.

I am thinking maybe a duff Starter Relay??? but I have tried to find this with no luck – have even pulled out all the 8 or so relays one at a time in the passenger footwell to see if that stops it turning over, but no.

Its driving me mad – please help.......

[mickeyw]

This does sound to me like a faulty relay, although in my experience relays normally fail to operate rather than fail to stop operating.

I don't own a Disco, but my RRC has relays hidden all over the place under the dash board, in the footwells and engine bay. What I am saying is that just because you have tried the ones you can see in one location, doesn't necessarily mean you have found the starter one.

The 1990 RRC has the starter relay fixed to the engine bay side of the passenger footwell. Maybe the Disco is the same.

[StuRox]

That's what I am thinking, given it failed to start, and now it won't stop starting - points to a component failure more than a wiring problem.

The only relay I have found in the bonnet is attached the fuse box on the drivers side near the battery. I have disconnected that one, and it still starts, although when disconnected, the glow plug light does not come on at all, even if I move the gear lever into drive, which makes me wonder if this might be the one at fault, as its a major relay with a microchip in it, and about 7 seven wires going into it.

Does anyone know where the 12v positive feed wire goes to that is on the starter motor, as then I can start to trace back through the starting process to see where the fault lies?

[fozsug]

The only relay I have found in the bonnet is attached the fuse box on the drivers side near the battery. I have disconnected that one, and it still starts, although when disconnected, the glow plug light does not come on at all, even if I move the gear lever into drive, which makes me wonder if this might be the one at fault, as its a major relay with a microchip in it, and about 7 seven wires going into it.

Does anyone know where the 12v positive feed wire goes to that is on the starter motor, as then I can start to trace back through the starting process to see where the fault lies?

The relay you describe sounds like the glow plug relay

The starter relay on mine is under the steering column

The 12v trigger from the starter goes to the starter relay and then ignition switch

[StuRox]

Cheers fozsug,

Any pics or its actual location of the relay, so I can have a look at it tonight?

[StuRox]

Well, here is the culprit that was causing me all the problems with the disco auto starting:-

You can see that the connectors and block are pretty corroded to say the least.

Also when I tested the relay, there is still a circuit across the to pins when it should be completely closed, so hence the disco trying to start all the time.

After a search on the internet I found that there were more relays behind the kickplate of the drivers foot well.

So pulled it off last night, and located the worst looking relay, pulled it out, and the glow plug light stayed on for its warm up, and no trying to start instantly – result.

Found a relay in my garage – a 30/40A one which I put in its place, and it would only start with a bit of wiggling, so I snipped off the connector block, and put new spade connectors on the wires, connected back up, and starts perfectly.

So my next question is, is there anyway of finding out what amp relay the knackered one is, to make sure the one I have put in will last?

[mickeyw]

I believe most of those yellow ones are 30A.

Given the state of that one in your picture I would say the footwell has got pretty damp at some time. Have you checked the condition of the other relays in that area?

[StuRox]

Thanks for that - have only just been given this link, which has confirmed what you have just said:-

E-bay relay

Yeah, good advice about the damp - had a quick scan through the others, and they seemed fine, but am going to have a good look at them all at the weekend in the day light to give them a good check over.

[idrisboyo]

That's what I am thinking, given it failed to start, and now it won't stop starting - points to a component failure more than a wiring problem.

The only relay I have found in the bonnet is attached the fuse box on the drivers side near the battery. I have disconnected that one, and it still starts, although when disconnected, the glow plug light does not come on at all, even if I move the gear lever into drive, which makes me wonder if this might be the one at fault, as its a major relay with a microchip in it, and about 7 seven wires going into it.

Does anyone know where the 12v positive feed wire goes to that is on the starter motor, as then I can start to trace back through the starting process to see where the fault lies?