Technical No ignition!

[RDS]

Hello all

I have no voltage at the coil and the ignition light will not illuminate. As a result, whilst the engine will turn over on the key, the engine will not start. The engine will start using a hot wire from the battery, however.

All the terminals at the multiway positive connector at the fusebox are conducting between themselves as expected. The ignition brown wire mod is in place.

Working forward from the battery, I can see 12v at the brown wire as it enters the ignition switch, ie on the switch pigtails, by probing the wire through the sheathing (I cannot seem to get to the terminal with the lock attached though).

I therefore need to see if there is voltage at the start of the red/black wire, (that Haynes shows as exiting the ignition switch and which then goes to Pin 2 of connector O on the fuseblock -embossed however as connector N), at the connector immediately after the ignition switch.

I do not see a red/black wire within the pigtails that enter/leaves the ignition switch, so I conclude that the red/black wire must be spliced to the blue/black wire (per the Haynes diagram) at a connector that I cannot see from below the steering column.
Anyone know where that connector is located?

Moving forward along the red/black wire from the switch to the fuseblock, I do not have voltage at the red/black wire at connector embossed N/Haynes printed O, at the fuseblock, but rather my Powerprobe tells me it is earthed out, which seems odd (this earth-out is not located at the points or via the tacho because I disconnected the green and pink wires from the coil to the distributor to test this).

I do not think I have tested (with battery disconnected) continuity between brown wire at the fusebox feed terminal and red/black wire at connector N/O) with the ignition key set to Run, so as to test the switch, but will do so to verify the operation of the ignition switch.

As red/black wire is not receiving 12v, the clock, heater blower, ignition light etc, and others fed via various fuses from that wire, including the pink 12v supply to the coil. Why is that?

If I apply 12v to the red/black wire using the Power Probe tool, there is no difference, ie still no operation of the items powered by the red/black wire.

Again, I cannot remember if I applied 12v to the red/black wire’s terminal on the fuseblock (N2) though, to see if the blower, clock etc operate….I will do so in next weekend session.

There is no voltage at the back of the pink wire at fuseblock embossed connector B8 (Haynes Q8) and again the Power Probe seems to indicate that it is grounded out.

I do have continuity between the .pink wire at the fuseblock and the same wire at the coil.

Adding all this together, I seem to get to the conclusion that I have a short to earth (rather than an open circuit) somewhere in the ignition circuit. But if that is correct, I do not understand how a direct hot wire to the coil allows the engine to run?

Am I correct in thinking that the only way I am going to narrow down this short (iof that is what it is) is by seeing if I have continuity to earth (battery disconnected, all intermediate connections disconnected) between each connection in the ignition circuit and earth?

I hope it isn’t the ignition switch as I do not fancy getting that off: both security bolts are sheared off as they are supposed to be.

Thoughts and magic wands welcome

Cheers

RDS

 

[g8rpi]

It does not sound like an earth problem. It does sound like a faulty ignition swich.

The shearhead bolts are not too hard to remove with a screw extractor and a cordless drill running in reverse.

Are you getting 12V on the red/black wire going to pin 2 on the fuse box?

Robert G8RPI.

 

[RDS]

hello Robert

many thanks for swift reply.

The top bolt to the ignition switch collar looks impossible to reach where it is: is the better way to drop the steering column at the nearest saddle so as to get a drill onto it?

Is the switch repairable or not able to be disassembled?

But why would the switch go with the brown wire mod helping it?

I get voltage at the brown wire at the switch but looking through my notes, none at the end of the red/black wire going to pin 2 on the fuse box.

Therefore if your diagnosis is correct (and I fear it is, because I had a one-off trouble a few weeks back):
1 there would be no continuity if I test across the brown wire to the switch (at the fusebox) and the red/black wire back from the switch (at the fusebox) when the switch is in the "RUN" position, whereas there should be continuity if the switch operated correctly. I will test this over the weekend.
2 applying 12v to the terminal on that pin 2, should bring back to life the pink wire, the clock and the blower. and the other items controlled by that feed. I half remember doing that with no success, but I will try that again at the weekend and report back.

If any of the above is incorrect analysis please do say!

Cheers

RDS

 

[Scotty1956]

Hello all

I have no voltage at the coil and the ignition light will not illuminate. As a result, whilst the engine will turn over on the key, the engine will not start. The engine will start using a hot wire from the battery, however.

All the terminals at the multiway positive connector at the fusebox are conducting between themselves as expected. The ignition brown wire mod is in place.

Working forward from the battery, I can see 12v at the brown wire as it enters the ignition switch, ie on the switch pigtails, by probing the wire through the sheathing (I cannot seem to get to the terminal with the lock attached though).

I therefore need to see if there is voltage at the start of the red/black wire, (that Haynes shows as exiting the ignition switch and which then goes to Pin 2 of connector O on the fuseblock -embossed however as connector N), at the connector immediately after the ignition switch.

I do not see a red/black wire within the pigtails that enter/leaves the ignition switch, so I conclude that the red/black wire must be spliced to the blue/black wire (per the Haynes diagram) at a connector that I cannot see from below the steering column.
Anyone know where that connector is located?

Moving forward along the red/black wire from the switch to the fuseblock, I do not have voltage at the red/black wire at connector embossed N/Haynes printed O, at the fuseblock, but rather my Powerprobe tells me it is earthed out, which seems odd (this earth-out is not located at the points or via the tacho because I disconnected the green and pink wires from the coil to the distributor to test this).

I do not think I have tested (with battery disconnected) continuity between brown wire at the fusebox feed terminal and red/black wire at connector N/O) with the ignition key set to Run, so as to test the switch, but will do so to verify the operation of the ignition switch.

As red/black wire is not receiving 12v, the clock, heater blower, ignition light etc, and others fed via various fuses from that wire, including the pink 12v supply to the coil. Why is that?

If I apply 12v to the red/black wire using the Power Probe tool, there is no difference, ie still no operation of the items powered by the red/black wire.

Again, I cannot remember if I applied 12v to the red/black wire’s terminal on the fuseblock (N2) though, to see if the blower, clock etc operate….I will do so in next weekend session.

There is no voltage at the back of the pink wire at fuseblock embossed connector B8 (Haynes Q8) and again the Power Probe seems to indicate that it is grounded out.

I do have continuity between the .pink wire at the fuseblock and the same wire at the coil.

Adding all this together, I seem to get to the conclusion that I have a short to earth (rather than an open circuit) somewhere in the ignition circuit. But if that is correct, I do not understand how a direct hot wire to the coil allows the engine to run?

Am I correct in thinking that the only way I am going to narrow down this short (iof that is what it is) is by seeing if I have continuity to earth (battery disconnected, all intermediate connections disconnected) between each connection in the ignition circuit and earth?

I hope it isn’t the ignition switch as I do not fancy getting that off: both security bolts are sheared off as they are supposed to be.

Thoughts and magic wands welcome

Cheers

RDS

Ok, just picked up on this for a wee while. - No Ignition.

The most likely culprit has to be 1. broken Ignition switch. 2. backed-out wire or crimp on either the 4pin Inn connector or as the red/white goes into the back of the fuse panel. 3. faulty fuse panel.

A short to earth would be very obvious as there are no fuses from the battery to the fuse panel and on these wires, you would smell / see / feel the heat!!
As I said, take care as you are dealing with unfused battery power on the ignition switch and its wiring (also that pink wire to the coil), any short to chassis = 1 less X1/9 on the road!

best of luck

 

[RDS]

With thanks to Robert and Scotty.

Looking at the Haynes diagram I checked for continuity between the red/black wire at pin O2 (aka embossed N2) and the brown wire connected to the +ve bus in the fusebox (did not connect with the switch in RUN), also between the red/black wire and the coil +ve pink feed) where I saw continuity. I also applied 12v to the red/black's pin and the coil and the other circuits listed above sprang to life, so the fault was with the ignition switch.

Why would it go bad? well, thinking about it, it is already under stress due to the lighting load AND in my case feeding the electric fuel pump - for the latter I will have to arrange a relay.

In case anyone is interested, the removal of the sheared bolts was quire problematical: there was but not enough room to drill out the bolts and i had no luck cutting a slot into the remains of the head with a Dremel.

The thing is that the bolts are screwed in from the gearstick side of the column but the only "easy access" is from the door side. That being the case, I found it a help to:

1. remove the cowl top and bottom - here I discovered someone has used 2 wood screws and 2 self-tappers - replaced on reassembly with proper screws
2. loosen the nuts on the bolts of the saddle holding up the steering column, just enough to allow it to drop a couple of inches and not strain wires
3. isolate the battery
4. disconnect the ignition switch connector
5. try to tap out the bottom lock bolt using a punch CLOCKWISE (because it entered from the other side) - failed as was too tight so had to drill out - this was not easy at all
6. try to tap out the top bolt - this worked - had it not, i was going to saw through the bolt via the now more open joint between the two halves of the lock and its clamp
7. putting the key to RUN released the column lock for extra clearance.

I felt that there was little to lose by taking the switch apart: push in pin, key to RUN, remove screw and prize apart. The two retaining interior screws are removed and the 4 brass tubes partly drilled out.

This gives access to the inner switch terminals which can be flicked out. Mine showed evidence of arc-ing but cleaned up easily; there was no melting of the surrounding plastic however. The inner terminals were flicked back in but beware the sprung vertical fingers flying off. My colleague had some very thin screws and small nuts (3 BA if I recall correctly) and these were used to secure the thinner brass tubes and the original screws went back in their previous position. The disk and the lock body can only go back together one way so there is no real danger of confusion there.

I did buy a replacement switch and was going to fit it however the resistances across the terminals on that are the same as the cleaned up switch so I will use that pending resolution of the other electrical issues.

M8 Allen head screws can be substituted for the shear bolts if desired - the heads drop right into the clamp's recesses.

Again, I need to plan for an ignition relay in due course.

Hope this helps someone!

Cheers

RDS