Practising wiring

[G60michael]

Hi there, some of those on Facebook may be aware that I'm having some electrical issues With my Blue 78 G60. Its mainly for the lights wiring, there very dull, and where the light switch on the dash plugs into the other section of the loom behind the bash there Is a few melted wires there.

As some may know, im pretty hopeless when it comes to reading wiring diagrams, I keep Trying but having no luck. To build up some confidence with wiring, I have been trying to get the 4WD-Light and Map Glove Box light working again, I know that they work right this moment (Plug to pieces of wire from the Battery to each light one (+) and one (-) terminals and they light up, But when you plug the lights into the Actual wiring loom there is no go

I have tried to work it out but no luck. Even tried to get the 4wd Light to work on my 77 Ute, it works when not plugged into the loom.

The wires in the wiring diagram from memory don't even match the wires colour specified in the loom.

Any Help please Thanks in Advance

[Johnny Roadkill]

G60michael, sounds like you need a multimeter. Measure the resistance of the wiring in the loom, open-circuits will be obvious, but you'll also be able to find the high-resistance wires that are either damaged or have poor connections somewhere in the circuit. Ground ( chassis ) connections are a common culprit, so don't forget those.

To give you a guide, for each ohm of resistance in a circuit you will lose a volt for every amp flowing through the circuit. To put that in real terms, a headlight ( draws about 5 amps - 60-odd watts divided by 12 volts ) will only see about 7 volts at the bulb if you have a lighting circuit with just one ohm of resistance, and the light will look like a candle behind smoked glass.

Remember that your meter leads will have some resistance too, so short the leads together and measure that resistance, and subtract that value from your real measurements when testing circuits.

cheers,
D

[Swerve]

Again get a multimeter, we discussed this 12 months ago, you can get cheapies for $10.

I think the simplest thing for you is to install a new relay and run new 12v cable "+"ve from the starter motor, into the relay and to your headlights. Take the old positive "+"ve at your headlights and take to the new relay.

This is the norm for adding spotties, maybe just ad spotties so you feel like your not trashing your cabling. G60 headlights are never bright in the first place , partially as the 12v "+"ve is not fed through a relay and goes from battery to starter, 6mm cable to amp gauge, back to fuse block, 6mm to headlight switch and then back to headlights. Alot of wasted cabling, resistance, hence low current draw at headlights. Hence a simple relay will solve 90% of the issues.

[RiverPatrol]

Many times when the headlights are dim the problem is with the ground/earth.