No Spark Following Some Tidying Of Wiring.

[SimonJ 2]

Hi,

 

Converted to 45s a couple of years ago and just got round to removing the excess injector-related wiring (as it connected into loom with three wires) this week. Surprisingly everything still worked. So, with confidence high, I started removing/tidying some other wiring that was just getting in the way:

 

(i) Tachometric relay and (I think) driving light relay had been in a box under (but slightly in front of) the battery tray which was broken so removed it and repositioned the relays.

(ii) Removed the middle wire from the TR as it had gone to the injector loom

(iii) Removed front indicator wiring (competition car).

(iv) Removed rusty earth straps on each side (bonnet to scuttle) as they were only connected to the scuttle.

(v) Turned FIA battery cut-out through 180 deg to allow for pull cable

 

Now I've been around cars long enough to know that things can go wrong for no apparent reason (none of the above appearing too risky) but now I've no spark.

 

Things that might be relevant:

(i) Rev counter doesn't move on cranking.

(ii) Green wire (112A) from tachometric relay does not seem to have power to/from(?) it when cranking though pump running (Facet - noisy).

(iii) Tachometric relay has one permanent and one switched live ok

 

I've a hillclimb on Saturday so would be grateful for any ideas or loan of a relay locally

 

Thanks.

Edited May 31, 2011 by SimonJ

[Anthony 1,003]

If you've no spark it won't be related to the tachymetric relay IMO.

 

Wire 112 is the negative pulse from the LT negative side of the coil. You won't thus see a positive on it.

 

Check that you've 12v ignition (positive) to the ignition amp and relay, a good earth for the ignition amp, and that you've a good, clean connection on the 3 pin yellow plug that connects to the dizzy for the timing signal.

[SimonJ 2]

If you've no spark it won't be related to the tachymetric relay IMO.

 

Wire 112 is the negative pulse from the LT negative side of the coil. You won't thus see a positive on it.

 

Check that you've 12v ignition (positive) to the ignition amp and relay, a good earth for the ignition amp, and that you've a good, clean connection on the 3 pin yellow plug that connects to the dizzy for the timing signal.

 

 

I tried a tester light on all the wires to/from the ignition amp plug (when disconnected) but nothing. I'm assuming there should be power at the brown wire, one of the three that doesn't come from the distributor? When you mention the relay do you mean the tachymetric relay? Power seems OK there.

 

Thanks.

[SimonJ 2]

Ended up leaving it into local garage and after much investigation turns out it was a fault in the cutout switch. At least it was nothing I did! Now know a fair bit more about the wiring which is good but even keener to get rid of more of it.