LT Coil Connections

[wildeep]

Would someone mind having a look at the LT leads on their car and confirm that mine are connected up properly. I have changed the spade connectors as they were corroded but am not getting a spark now. Any suggestions?

[greenv8s]

Check the polarity at the coil. You should have permanent 12v on the +ve terminal, and the -ve terminal should be earthed intermittantly via the ignitin module when the engine is cranking. What are those black things in the picture? They look like the resistive suppressors used i the LT signal to the ECU. Mine doesn't have anything like that in the feed to the coil; has yours always had those? I would try without them anyway.

[wildeep]

I have no idea what those things are, they are branded lucas, they have always been there. I have checked and i do not have 12v at the coil. I dont have 12v at any of the leads either. Is there a fuse for the LT at the coil?

>> Edited by wildeep on Friday 6th August 16:44

[HarryW]

The 12V feed may come via the immobiliser/alarm before the coil. Do you have intermittant problems with that at all, just clutching at straws that it might be coincident , normally the golden rule is go back over what you've just done, before it stopped working.

Harry

[wildeep]

I did have immobilier problems until i removed it so i can discount that.

[david beer]

Do you voltage at the other end of these ? Could be diodes in which case they need to be round the right way.I have not seen them before so i would do as Pete said.

[wildeep]

Hi David. I get 12v to the black wire with the ignition on, nothing at either of the white/blue wires. I still get 12v with the diode thingies connected so they must me someting else, maybe some sort of noise supressor?. The connector with 2 wires coming out goes to the coil, one to pos the other to neg.

[HarryW]

Daft question, the king lead is fully home on the coil and connected to the dizzy, isn't it .

Harry

[wildeep]

Yup all HT leads connected properly. Have noticed that the tacho doesnt move when cranking the engine over either.

[HarryW]

Checked the fuses, a 15A (blue) one I think feeds the coil.

H

[greenv8s]

From your picture the black wire is connected to one of the white/blue wires, how do you manage to have 12v on the black wire and nothing on the white/blue wire?

[wildeep]

i checked the voltage when they were disconnected. Think i have managed to figure out what they all are. The black is the 12v supply to the coil and the two blue/white wires go to the ecu and to the tacho. I think the blue/white wires should go to the coil neg and the black to the coil pos. Sound right?.

[pebbledash]

greenv8s said:

From your picture the black wire is connected to one of the white/blue wires, how do you manage to have 12v on the black wire and nothing on the white/blue wire?

if its a resistor or a diode its may have gone open
circuit..
I will pull my griff apart (they are in a mass of pvc tape) on sunday in no one else posts an answer and tell you what they are. (Elec Eng Training )

[wildeep]

All sorted now. For reference, the black wire goes to the coil positive, the two white/blue wires go to the coil negative. Going to try and shorten them a bit as they are about a metre longer than they need to be. Thanks for everyones help.

>> Edited by wildeep on Saturday 7th August 09:28

[HarryW]

Good to see, proves the theory 'always checked what you last did' then .

Harry