No power to coil

[OddJobBob]

Oh dear! You have a years trouble free fun in your van and then three problems come along at once. Firstly, had to fit a new starter motor (a mirror came in very handy!); secondly, £220 to get through the MOT - exhaust and handbrake. Now to top it off, the missus broke down having dropped the kids off at school. Basically, all dash lights come one when the ignition is in the first position. However, turn the key and the engine turns over but won't fire. She called the RAC out and whilst the couldn't fix it, they did get the van started to get the missus home. From what the missus tells me, RAC man said no power is getting to the coil. The RAC man got it started by attaching a wire to the coil with a fuse and the other end to that black box of wires and connectors at the rear of the engine bay. With this wire in place, the van started normally with the key. However, the RAC man said that when she got home, the missus should remove the fuse from the wire to get the van to stop. Turning the ignition off wouldn't stop the van. Unfortunately, when she removed the engine cover, the wire came off from where ever it was attached to in the back box of wire. Anybody experience this or know which of the many wires I need to check for continuity. Many thanks.

PS 1.9 DG.

[kevtherev]

low tension circuit, so suspect an ignition switch fault..after twenty years of turning you on , they get a little worn. or the connection is broken.

when switched on the current flows from the battery through the switch to the coil

connections...
from the coil, green wire, then to pin 5 on the 7 pin connector in the junction box. (good bet!) then green wire, carrying on to..
relay plate, multi pin connector E contact 13... changes to a red / black wire to the ignition switch

[OddJobBob]

Thanks for the info kevtherev. Will dig out my multimeter at the weekend and see how far I get.
Cheers
Rob

[OddJobBob]

I have a looked at this for a couple of hours and am a bit stumped.
The RAC man got the van going but connecting a live feed to terminal 15 on the coil. Having looked at the coil, there are two separate connections to terminal 15. One connector carries a single back wire to the ignition amplifier (I think this is what is is called). The other connector on terminal 15 has two wires attached to it. A thick and thin black wire. Both these go back to a single connector in the connector box. I have tested continuity along the thick/thin black wires between the coil and this single connector. There is continuity. I have checked the connector it goes to and find 12v when the ignition is on. For some reason, this 12v doesn't make down the thick/thin black wires to the coil end. I just don't understand it!. Does the thick/thin wire connect else where hidden under the insulation? Why is there a thick/thin black wire. Something is going on. Help!!





Would it be safe to put a temporary wire from this wire where I have found 12v straight to the coil to see if the van starts?

Cheers

Rob

[BOXY]

Have you only got a single wire connected to the amplifier?

[OddJobBob]

Sorry Boxy. Bit of a misleading photo which shows the connector to the amplifier removed. The thick green wire from terminal 1 on the coil goes to (or from) the amplifier as does the single black wire on terminal 15. The thin green on terminal 1 goes to a 7 pin connector in the junction/connector box and the thick and thin black wires which share a common spade connector on terminal 15 goes to a single connector in the junction/connector box. Its this wire that doesn't seem to carry the 12v which it appears to receive in the junction/connector box.
I can't tell if these wires connect to other wires hidden in the plastic sleeving that all the wires are bundled in.

Cheers

Rob

[BOXY]

I haven't got my manual to hand, but I was under the impression the +12ve to the coil came in on the green wire when the ignition is switched on. and the black wire(s) are the route to earth when switched by the distributor? Check the end of the coil to see which is the +ve positive connection. If you connect any 12v feed to this terminal the engine should start but you won't be able to switch the engine off because you've by-passed the ignition switch.

[OddJobBob]

Hi Boxy. Kevtherev also said ignition comes on the green wire but I'm confused as to how the RAC man got the van going because he connected a 12v wire to terminal 15 on the coil which is terminal that the black wires are connected to. The green wires are on terminal 1 of the coil. I really must buy a haynes manual!!

Cheers

Rob

[kevtherev]

there are two greens.. one thick one thin.. thin goes to the ignition switch... thick goes to the icu.
thick black wire straight from the coil.. goes to the icu (pin 4)
the thick black wire where the two thin black meet at the connector, goes to the ignition switch

one of those thin black wires goes to the coil, the other goes to... the thermoswitch for the manifold heating

there must be a problem with the connector if you get no power through it

[OddJobBob]

Sorry to bother you again people, but I'm still having no luck tracking down the reason why my coil doesn't get 12v from the ignition. I'm starting to get van withdrawal symptoms!!

One thing of note is that when the ignition is switched on, I don't hear a click from the inlet manifold preheating relay. I have tested the relay by connecting it directly to the battery and it does click. Could that be a problem?

Also, the thick black wire that connects at connector T1a from the ignition is only carrying 11.53v whereas across the battery terminals, I get 12.38v. Is this a problem?

Anyway, for what ever reason, this voltage doesn't get down the wire(s) to the coil. If I connect the black wire from T1a straight to the coil, the van doesn't start but if I connect 12v to coil, the van does start.

One thing hindering me is my lack of understanding of the Haynes manual wiring diagram. I have read it and read but apart from realising I need glasses, I am none the wiser. For example, on page 12.23, a 0.5 black wire from the coil goes to a rectangle with the number 20 in it and another 0.5 black wire from the coil goes to a rectangle with 24 in it. What does it mean??? I thought the diagram went to the next page, 12.24 to the number on the bottom line - only problem is that the black wire suddenly goes to black and that cant be right. Kevtherev said one of the 0.5 black wire goes to the thermoswitch for the manifold preheating but I cant work out the links from the diagrams.

Thanks for any help.
Cheers
Rob

[Oldiebut goodie]

Also, the thick black wire that connects at connector T1a from the ignition is only carrying 11.53v whereas across the battery terminals, I get 12.38v. Is this a problem?

For a start - your battery is flat.

[OddJobBob]

Thanks for the reply. I realise the battery is a bit low. Too much cranking and not enough starting!

Cheers
Rob

[OddJobBob]

Had one final go today trying to get the old girl running. Not entirely sure what I did but she burst into life! I had 12v at the junction box in the engine bay but this didn't get to the coil. I removed the various connectors that went to the carb/preheat switch etc and remade a few other connectors and that was that. What a relief!

Cheers
Rob

[kevtherev]

......there must be a problem with the connector if you get no power through it

ahem

well glad your sorted

[OddJobBob]

Cheers kev. Your posts were of more help than the cryptic Haynes manual wiring diagrams!
Rob.