ECN Forum Forums General Topics of the Trade General Discussion Area Auto electrics

Be careful soldering joints in an Automotive enviroment. Vehicle usually produce vibrations which could lead to the soldered joint failing. A high quality tap or butt connector is a better option IMHO.

Joe

[This message has been edited by Joe2 (edited 09-20-2003).]

Guys,
I have a question.
I installed a CD player + Changer into a car (Toyota Marino), for a mate yesterday.
And as we all know, cars don't usually come with wiring diagrams.
But, the question I have is this:
Is there a standard colour coding system for the Audio speakers wiring, where these are run in the same loom as the 12V wiring?.
The reason I ask this is because this was the one thing that took so long to figure out, I ended up having to remove the speakers, individually (and these had different wire colours again!) and "belling the wires out".
And the original AM/FM Radio was no help at all.
You'd think that (like trailers), there would be a standard colour code system, but I'm not too sure.
Can someone please help me in this respect?

There's no single standard unfortunately, but many modern systems with four speakers do seem to share certain traits.

If you can find the bunch of eight wires going to the speakers you'll often find that they use one color for the front and another for the rear. The grounded sides are often plain wires, and the "live" sides get a stripe: one color for right, another for left.

An example might be:

Front left: Gray/Blue, Gray
Front right: Gray/Red, Gray
Rear left: Green/Blue, Green
Rear right: Green/Red, Green

Substitute other colors for any of those at the manufacturer's whim and you get the idea. I've seen it done the other way as well, where they use the base color to indicate left/right and the stripe indicates front/rear, although that doesn't seem to be so common.

If you can identify the eight speaker wires from the bunch, you can check which ones go to which speaker with an ohmmeter, so long as the environment isn't too noisy. Set your meter on a low ohms range and as you apply it to each pair you'll hear a slight rustling noise from the appropriate speaker. The stripes should then let you get the phasing correct, unless someone has fiddled with the connections at the speakers themselves.

I've soldered automotive wiring for a goodly number of years and never had one fail. Crimp splices, on the other hand, corrode and break with astounding regularity. If they are going to see any wetness, I have taken to filling them with RTV before I install. I am also prety careful with the cardinal rule of soldering: Make the connection mechanically secure before you solder. With the complexity of modern car wiring, most factory manuals now devote a section to wire repair and replacement. The instructions hardly ever say to strip it back and crimp on a red butt connector. Hey, I use scotchlok taps occasionally but I'm not at all suprised if I have to redo them.

I have a '70 Nova drag race car that the only wiring in it is mine. I have been working on cars since I can rememeber and motorcycles even before that.
This is not at all to say I am an auto tech but I can hold my own on pretty much anything older and do OK on new stuff. Code scanners are a wonderful tool if you know how to use them.

Update on lighting wiring, from having to look at a late-ish model Ford Mondeo recently. This has got to be the most diabolical and convoluted system ever devised!

The lighting switch is rotary on the dash and has four positions. One position clockwise from off gives parking/tail lights and fully clockwise turns on the headlights, although these will only work when the ignition is on. The parking light setting gives dim low-beam headlights when the ignition is on.

The park/tail lights stay on when the key is turned back to accessory, but switching off and removing the key results in no lights at all.

To leave the car with parking lights on, you have to turn the light switch to the extra position, counterclockwise from off. But if you then put the key back in and turn it to the accessory position, the lights go out again!

Talk about taking a simple system and making it needlessly complicated to use.