Helpful hints when dealing with wiring

[BlownMGB-V8]

We might want to make this a sticky thread if there is adequate contribution. Anyway, lots of info we can put here and you have to start somewhere. So as a preamble, the state of modern automotive wiring has advanced a bit since the 60's and we can take advantage of those advances. So first a few general considerations:

Oxygen is the enemy of wiring conductors. Anything you can do to keep it out is going to improve reliability. As a general principle we could hardly ask for a better one and it applies to any conductor, anywhere and for any purpose, external or internal.

All connections are potential failure points (PFP). Any transition in a conductor is a PFP. Any change in conductor type, material, cross section or area is a PFP. Any change in insulation is also a PFP, as is any recognized failure of the conductor itself. So we see for example that a common one conductor bullet connector has at minimum 7 and really 8 PFPs. 2 insulation transitions, 1 spring connection (subject to breakage at 2 points), 2 solder or crimp joints, and 2 friction/spring joints. Oxygen increases the chance of failure at most or all of these PFPs. Even a crimped and/or soldered gas sealed connector has 3 PFPs but that is a marked improvement especially when the O2 is kept out.

Towards that end, adhesive and heat shrink sealed connectors are highly recommended as well as cross linked insulation on the wires because it is tougher and lasts longer. Gas sealed connectors are a good choice any place that they can be used. Wherever a conductor is exposed, a thin coating of silicone sealant of some type will help reliability. Probably our greatest challenge here is with switches and we are limited in our options but in many cases upgrades are possible.

Bullet connectors *can* be used but are prone to failure. This can be helped with silicone sleeves and a good anti-corrosive but be advised that dielectric grease does not have any anti-corrosive properties and is really no better than vasoline for this purpose. GuAl Gel is one popular product, there are others.

If you find you have a need to substitute wires, and let's face it there always seems to be a reason why we can't use the right colored wire, be it aftermarket additions or whatever, it's a good idea to think about which end of the wire is likely to get attention in the event of a wiring issue. That's the end you'll be trying to identify so it should be as consistent with the vehicle wiring as you can get it. For instance you might have a blue wire from a noise filter powering your sound system and be tempted to use a blue/w or blue/r wire to lengthen it but those colors are for the headlights, so later troubleshooting could get very confusing very fast. OEM radio feed is w/g and then w/p so a better choice would be white (even though that is for ignition) if you had to use a solid color, or at least something distinctly different from standard vehicle wiring. Sometimes we do have to compromise. That way you'd at least be looking in the right area at a small circuit rather than wondering why your seat belt wires are connected to your radio.

If you have additional suggestions please contribute.

Jim