Spitfire 1500 Engine Bay Wiring & Head Studs

[Chambers]

Over Christmas I want to get the Spitfire running, it turns over and was running before I moved the car home about 6 months ago, in that time I've messed with the wiring and just cant remember how it goes!

 

Coming from the ignition coil I have the wire (shown between the purple dots) connected to the dizzy.  Granter its only twisted for now because I didn't want to spade it until I checked.

My question that is stumping me is what is the spare spade shown between the red dots?

 

Also,

 

when I got the head done years ago the garage put the studs back in the wrong way (short ones at the back) so the lifting eye wont go on,  I'm going to change these back to how they should be but wanted to check I can do this with a stud extractor tool while the head is on and wanted to check, are there reverse thread or normal?

 

thanks

[RobPearce]

I can't see the dots you refer to so I'm not quite sure which wires you mean.

You should have two wires on the + terminal of the coil - probably sharing a connector - one of which is a resistance wire from the ignition switch and the other is a short link to the fourth terminal of the starter solenoid. That's a bypass for the resistor to boost HV during cranking.

On earlier cars, there would only be one connection to the - terminal but if yours has an electronic rev counter then there will be a second connection for that.

Or is the "spare spade" you mention the one that's cable-tied to the loom by the fuel pump? If so, that looks like an addition or some nasty meddling.

As to the studs, you should be OK to swap them with the head on but try to do one pair at a time and re-tighten the nuts before doing the other pair, so as not to remove all the clamping force. Re-torque the whole lot afterwards (just back them all off a quarter turn then tighten to correct torque in the official sequence). The studs screw into the block with a normal  thread and don't need to be done tight, just finger tight to fully home. The torque is all done on the nut.

[Chambers]

Thanks, for the help, turns out I used the photos without the dots on!

 

The correct photo is below

[RobPearce]

Ah, OK, so it's the non-standard wire you're confused by. Can you identify the colour of the wire itself? The terminal is not original but the wire possibly might be, and if so its colour should identify it (with reference to the WSM wiring diagram).

[Chambers]

So I've done a bit more digging, hopefully you can help Rob, or someone can.

 

From the points on the dizzy is connected to the bottom right (passenger side) of the coil

 

The 'phantom' unknown wire is solid green and cutting back a bit further up the loom it looks like its pretty standard or been cut in well so it can't be seen!

 

 

I've also noted the green and brown and white and brown which I believe go to the reverse switch from memory and looking at the connector

 

Any help would be great!

[RobPearce]

Oh, I didn't intend you to destroy your loom wrap! I only wanted a wire colour.

The reverse light switch is the Green/Brown and plain Green wires.

Get yourself a proper workshop manual, with a copy of the wiring diagram. There are colour versions of most of the wiring diagrams on the web but they're not always accurate on small details like which fuse is which. However, as a basic bit of "old British car knowledge", it's worth memorizing a few of the standard Lucas colour codes (again, there are full lists out there if you Google):

- Brown    = Live, permanent, un-fused (i.e. direct to the battery)

- Purple    = Live, permanent, fused (mostly supply to horns and headlights)

- White     = Live, ignition switched, un-fused (i.e. off the ignition switch and to coil +ve etc.)

- Green     = Live, ignition switched, fused

- Black     = earth

A wire that's two colour where the primary is one of the above is usually (but not always) a switched feed to something off that circuit, so a green with brown tracer is +ve feed to the reverse lights, from the reverse light switch, which is powered off the green (fused, ignition switched) supply. Sometimes, though, it's the other side of the circuit - e.g. green/black on earlier cars is the wiper motor ground side, because the circuit runs from green supply to the motor, then down to the switch, to ground.

I think the white/brown wire is the oil pressure warning switch connection. The Haynes diagram for the 1500 doesn't give a colour for that (and labels the switch completely wrongly!) but it's correct for the earlier models and isn't likely to have changed.