1985 Defender 90 ROW with a patch work of non-OEM wiring.

In an effort to resolve a “no start / no crank” situation, I removed the Ignition Switch (Lucas 162SA aka PRC2735) and when pulling out the heavy lock barrel, I accidentally dropped the piece and most of my wires came off, before I could take a picture of the corresponding switch terminal #s and there corresponding wire colors on my truck.

I’ve ordered a replacement PRC2735, given this area of the truck is now apart and the replacement switch seems like a reasonable preventive maintenance investment. At the moment I can’t test whether the existing switch has failed, because I am unsure which wire colors correspond to Switch Terminals 1, 3, 4 and 5. For what its worth, Terminal 2 (a 10mm spade) stayed connected to an Orange wire, which based on research on this site, should be the Glow Plug Feed. Also my truck was only using 4 Wires, so there is an extra terminal on the Ignition Switch which must not have been used.

Is it possible to solve this puzzle; (1) based on the Gauge of the wires that are disconnected and coming out of the dash and/or (2) the disconnected Wire colors and there corresponding gauge:

-Brown 12 Gauge (6mm spade)

-Red & White 12 Gauge Wires Joined on the spade connector (terminated with single 6mm spade)

-Red/White (a single wire with two colors) 16 gauge wire (6mm spade)

# - Purpose/Feed Wire Color

1 – Ignition (6mm) - ??????

2 – Glow Plug (10mm) - Orange

3 – Fuel Solenoid (6mm) - ??????

4 – Starter (6mm) - ??????

5 – Perm 12v (10mm) - ??????

I would appreciate any help or advice to match-up the correct Switch Terminals to the correct wire feeds on my truck.

A picture of what I’m looking at:

The picture

Another question and some information. I have confirmed with a volt meter that the Brown wire (12 gauge) is carrying 12v (constant w/out turning key etc.), so this will be connected to Terminal 5 on the switch (input). Since Terminals 3 and 4 are outputs , does it matter if the Starter Solenoid and Fuel are incorrectly wired to either of these switch outputs? If I put this back together and turn the ignition, with the fuel and starter wires “reversed” (trial and error) ... is this a bad idea?

steve2286w Thanks!

Hope it helps forgot to add search On all the forum for “ wiring ignition switch”
You’re not the first to have a problem

Solved ... truck running, thanks for the help.