Wiring diagrams or electrics information thread - Discussion

[Robsey]

Wow - 100 Amps!!
Really?

75mV... Hmm so we are talking 7.5 watts.
Doesn't sound so bad when it is written that way.

At that level of current, you are probably talking a 4mm CSA wire fused directly to the battery positive terminal.

An ammeter is the only device that I have ever had an issue with. I fried the wires behind my dash, when I used standard 1mm wire.
Smoke and acrid smell filled the cabin whilst driving past Manchester Airport at 70 mph on the link road towards the M56.
That was in 1989 in my first car.
I would like to think that my wiring is much better and safer 27 years later.

You would need an equally sturdy wire for the ground wire.

[ilovedmymantas]

Thanks Robsey,
the meter's lcd. 0-20V,100A , I don't think there's a small in-built shunt
The reason I got the high amp one was, in my mind, that it would be safe enough with the cdx alternator. I read about shunts, fried meters without them, neg rather than pos fitting till my head was spinning (google overload!)
Sometimes too much knowledge is a dangerous thing, especially when it's conflicting
I guess I was hoping the easy ( and safe ) solution would be something like take the feed from your unused heated seat plugs in the dash, or lighter socket ( anyone selling magic beans )
Since that doesn't seem likely would this be the safest option in principle, or is there a better one ?
http://www.waterexplorer.co.uk/hosted/d ... -shunt.pdf

out of my depth but I like to try

-matt

[Robsey]

As someone has kindly done a useful How 2,
I would say yes go for it.

It has done all the brain work for you.

[ilovedmymantas]

ok - thanks for your advice .

[Robsey]

As many will know, I have done a few electrical jobs in the past few months - long over due...

So some new How 2s are on the system,
Such as retro fitting cruise control from a 4 pot Vectra-B petrol car.

And I am close to finishing the retro-fit of a 3rd brake light.
Mounted centrally at the bottom of the rear screen.

With regard to both of these projects, I have moved my thinking with regards making looms.

Originally I had always used good quality pvc insulation tape cut to approx 10mm wide to spiral bind my looms.

For the cruise and tailgate harness looms, I have started using 9 mm wide "Tesa" fabric harnessing tape.
It is for me a total improvement on pvc.

The fabric is not affected by hot and cold, so does not unwind itself when the glue gets warm and sticky, or become stiff when cold.

Also being a woven fabric, it is "softer" than pvc, and so significantly reduces vibration / tapping against the back of the dash panel etc.

And - it looks tidier and more professional.

Of course I do still use soldered joints and heat shrink tubing. But the tesa tape hides all that beautifully.

[Robsey]

A quick cheat.

I finished fitting a reversing camera to the wife's Vectra-C today.
Nothing special in that you may say.
And you are indeed correct.

The cheat was getting the camera loom from the back bumper, through the rear body skin into the load area.

I was determined not to drill another hole through the rear body skin.

So the plan was to use the existing number plate light grommet in the rear body skin.

I had to undo some factory fitted pvc tape wrapped around the grommet where it tapers down onto the cable.

That done, I then stretched the inner bore of the grommet with circlip expanding pliers.

Fed the connectors and splitter through the expanded hole, release afterwards and we have a nice tidy, undamaged grommet.

Re-wrapped some pvc tape around the grommet taper, and re-fitted the grommet into it's hole in the rear skin.

Job done, with no drilling, cutting or bodging.
Brilliant!!

And to complete the post - camera works perfectly when reverse gear is selected.
But the number plate illumination is affected a little by the camera casing obstructing light output from the left number plate light unit.

[Robsey]

I pulled out a bag full of unfinished projects / ideas.
Oh eck, what was I thinking?

Here is a project idea that may or may not make it to my car, but could inspire ideas for others.

- After spending cold wet winter nights looking at the Haynes' manual
(Yes, I am odd like that) I came up with a few ideas.

I may get round to doing proper How2's in the next few months, we shall see.

Here is a written summary for window lifter switches.

Adding a "White Wire" to the Window Lifter Switches. (2 Switch Panels).

Why do this? you may ask.

Well, Possibly for fitting door handle mounted window lifter switches, as described in Envoy CDX's How 2.

Note that the 4-switch unit is already fitted with the white wire. (For powering the rear windows).

You could wire to the fat red wire in the door loom, but this is permanently live.
Not a good idea.

To use the same on/ off logic control as fitted to the centre console switches, you would need to add the white wire as fitted on the four-switch panels.

The three wires needed are -
White wire from centre console panel.
Grey / Green for window lift.
Blue / Red for window lower.

Obviously you would need switches for the rear doors on Astra-F or Cavalier... possibly a few others.

With a 2 switch unit, you would need to solder a wire to the main bus-bar inside the switch unit.
Run this wire to your centre console connector (X40 pin 1 rings a bell).

I had soldered a grey / green wire to a bare-exposed leg of the bus-bar.
(Top right of the switch / image).
Suppose I should change this to white really...





From here, the blurb is the same for 2 and 4 switch units... except the 4 switch unit will have an isolator button switch to cut power to the white wire.

So run the white wire(s) to the main connector in both front door frames, and feed a wire from the door connector to the switches mounted in the front door handles. (Not if you have electric mirrors).

Then add wires from the window motor connector for each of the other colours.

In theory, that should provide door handle mounted window lifter switches.

Another possible use is to add any item that you want to become live when the ignition is on, or the driver's door is open.